ci: drop container: for Godot jobs, install via composite action

The first Gitea Actions runs failed at actions/checkout@v4 because
barichello/godot-ci:4.6 ships without Node.js, which the JS-based
checkout action requires. Rather than chase a Godot CI image that
bundles Node, drop the container: blocks entirely: the default
catthehacker/ubuntu:act-latest runner image already has Node /
Python / git / JDK, and Godot is installed per-job from the
official GitHub release.

Pulled the install logic into a local composite action at
.gitea/actions/setup-godot/ to avoid duplicating 15 lines of wget +
unzip across the three Godot-using jobs. Inputs:
  - version  (default 4.6)
  - templates (default false — export jobs flip to true)

Other tweaks:
- export-android now puts $ANDROID_HOME under $GITHUB_WORKSPACE so
  no sudo is needed; editor_settings-4.tres interpolates that path.
- export-android writes the keystore under /tmp instead of /root
  (catthehacker runners don't run as root).

README updated: jobs table reflects the new "Tooling installed by the
job" column, prerequisites no longer mention the Docker image, and
known-issue #1 is closed out with the dated fix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -9,7 +9,6 @@ on:
 
 env:
   GODOT_VERSION: "4.6"
-  GODOT_IMAGE: "barichello/godot-ci:4.6"
 
 jobs:
   # ---------------------------------------------------------------------------
@@ -18,11 +17,13 @@ jobs:
   validate:
     name: Validate GDScript
     runs-on: ubuntu-latest
-    container:
-      image: barichello/godot-ci:4.6
     steps:
       - uses: actions/checkout@v4
 
+      - uses: ./.gitea/actions/setup-godot
+        with:
+          version: ${{ env.GODOT_VERSION }}
+
       - name: Import project (parses every .gd / .tscn)
         run: |
           godot --headless --import 2>&1 | tee /tmp/godot-import.log || true
@@ -72,8 +73,6 @@ jobs:
     name: Export ${{ matrix.platform }}
     needs: validate
     runs-on: ubuntu-latest
-    container:
-      image: barichello/godot-ci:4.6
     strategy:
       fail-fast: false
       matrix:
@@ -93,6 +92,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - uses: ./.gitea/actions/setup-godot
+        with:
+          version: ${{ env.GODOT_VERSION }}
+          templates: "true"
+
       - name: Restore import cache
         uses: actions/download-artifact@v3
         with:
@@ -114,7 +118,7 @@ jobs:
           retention-days: 14
 
   # ---------------------------------------------------------------------------
-  # 4. Android export — needs JDK + Android SDK on top of the Godot image.
+  # 4. Android export — Godot + JDK 17 + Android SDK installed in $HOME.
   #    Provide ANDROID_KEYSTORE_BASE64 as a Gitea secret for a stable signature;
   #    otherwise a fresh debug keystore is generated on each run.
   # ---------------------------------------------------------------------------
@@ -122,21 +126,25 @@ jobs:
     name: Export Android
     needs: validate
     runs-on: ubuntu-latest
-    container:
-      image: barichello/godot-ci:4.6
     env:
-      ANDROID_HOME: /opt/android-sdk
-      JAVA_HOME: /usr/lib/jvm/java-17-openjdk-amd64
+      ANDROID_HOME: ${{ github.workspace }}/.android-sdk
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install JDK 17 + unzip
+      - uses: ./.gitea/actions/setup-godot
+        with:
+          version: ${{ env.GODOT_VERSION }}
+          templates: "true"
+
+      - name: Install JDK 17
         run: |
-          apt-get update
-          apt-get install -y --no-install-recommends openjdk-17-jdk wget unzip
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends openjdk-17-jdk
+          echo "JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64" >> "$GITHUB_ENV"
 
       - name: Install Android command-line tools + SDK
         run: |
+          set -euo pipefail
           mkdir -p "$ANDROID_HOME/cmdline-tools"
           wget -q https://dl.google.com/android/repository/commandlinetools-linux-11076708_latest.zip -O /tmp/cmdline.zip
           unzip -q /tmp/cmdline.zip -d "$ANDROID_HOME/cmdline-tools"
@@ -149,14 +157,14 @@ jobs:
         env:
           ANDROID_KEYSTORE_BASE64: ${{ secrets.ANDROID_KEYSTORE_BASE64 }}
         run: |
-          if [ -n "$ANDROID_KEYSTORE_BASE64" ]; then
-            echo "$ANDROID_KEYSTORE_BASE64" | base64 -d > /root/debug.keystore
+          if [ -n "${ANDROID_KEYSTORE_BASE64:-}" ]; then
+            echo "$ANDROID_KEYSTORE_BASE64" | base64 -d > /tmp/debug.keystore
           else
             keytool -keyalg RSA -genkeypair -alias androiddebugkey -keypass android \
-              -keystore /root/debug.keystore -storepass android \
+              -keystore /tmp/debug.keystore -storepass android \
               -dname "CN=Android Debug,O=Android,C=US" -validity 9999
           fi
-          sed -i 's@keystore/debug=".*"@keystore/debug="/root/debug.keystore"@g' export_presets.cfg
+          sed -i 's@keystore/debug=".*"@keystore/debug="/tmp/debug.keystore"@g' export_presets.cfg
 
       - name: Write Godot editor settings (Android SDK / JDK paths)
         run: |
@@ -164,9 +172,9 @@ jobs:
           cat > ~/.config/godot/editor_settings-4.tres <<EOF
           [gd_resource type="EditorSettings" format=3]
           [resource]
-          export/android/android_sdk_path = "/opt/android-sdk"
+          export/android/android_sdk_path = "${ANDROID_HOME}"
           export/android/java_sdk_path = "/usr/lib/jvm/java-17-openjdk-amd64"
-          export/android/debug_keystore = "/root/debug.keystore"
+          export/android/debug_keystore = "/tmp/debug.keystore"
           export/android/debug_keystore_user = "androiddebugkey"
           export/android/debug_keystore_pass = "android"
           EOF