ci: fix lint venv, drop artifact cache, fix Android sdkmanager pipe

Three follow-up fixes from the first non-container run (#10):

- lint: Ubuntu 24.04 / Python 3.12 enforces PEP 668, so
  `pip install --user` exits with externally-managed-environment.
  Install gdtoolkit into a throwaway venv at /tmp/gdlint-venv
  instead.

- exports: drop the .godot/ artifact cache shared between
  `validate` and the export jobs. Gitea's artifact service returns
  404 on actions/download-artifact@v3 (v3 protocol incomplete on
  this server). Each export job now runs its own
  `godot --headless --import` before exporting — costs ~30s but
  avoids the failing cross-job artifact dependency.

- export-android: `yes | sdkmanager --licenses` returned 141
  (SIGPIPE) under `set -o pipefail` because sdkmanager closes
  stdin after accepting all licenses while `yes` keeps writing.
  Feed a finite `printf 'y\n%.0s' {1..50}` instead.

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

.gitea/workflows/build.yml

@@ -36,13 +36,6 @@ jobs:
             exit 1
           fi
 
-      - name: Upload import cache
-        uses: actions/upload-artifact@v3
-        with:
-          name: godot-import-cache
-          path: .godot
-          retention-days: 1
-
   # ---------------------------------------------------------------------------
   # 2. Static analysis — gdlint from Scony's gdtoolkit (Python, no Godot).
   #    Runs in parallel with `validate`. Exports do NOT depend on this job,
@@ -58,8 +51,9 @@ jobs:
 
       - name: Install gdtoolkit
         run: |
-          python3 -m pip install --user "gdtoolkit==4.*"
-          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+          python3 -m venv /tmp/gdlint-venv
+          /tmp/gdlint-venv/bin/pip install --quiet "gdtoolkit==4.*"
+          echo "/tmp/gdlint-venv/bin" >> "$GITHUB_PATH"
 
       - name: Run gdlint
         run: gdlint scripts db scenes
@@ -97,11 +91,8 @@ jobs:
           version: ${{ env.GODOT_VERSION }}
           templates: "true"
 
-      - name: Restore import cache
-        uses: actions/download-artifact@v3
-        with:
-          name: godot-import-cache
-          path: .godot
+      - name: Import project
+        run: godot --headless --import || true
 
       - name: Prepare output dir
         run: mkdir -p "${{ matrix.artifact_path }}"
@@ -149,7 +140,9 @@ jobs:
           wget -q https://dl.google.com/android/repository/commandlinetools-linux-11076708_latest.zip -O /tmp/cmdline.zip
           unzip -q /tmp/cmdline.zip -d "$ANDROID_HOME/cmdline-tools"
           mv "$ANDROID_HOME/cmdline-tools/cmdline-tools" "$ANDROID_HOME/cmdline-tools/latest"
-          yes | "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --licenses >/dev/null
+          # `yes |` returns 141 (SIGPIPE) under `set -o pipefail` once sdkmanager
+          # closes its stdin — feed a finite stream of "y" answers instead.
+          printf 'y\n%.0s' {1..50} | "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" --licenses >/dev/null
           "$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" \
             "platform-tools" "platforms;android-34" "build-tools;34.0.0" >/dev/null
 
@@ -179,11 +172,8 @@ jobs:
           export/android/debug_keystore_pass = "android"
           EOF
 
-      - name: Restore import cache
-        uses: actions/download-artifact@v3
-        with:
-          name: godot-import-cache
-          path: .godot
+      - name: Import project
+        run: godot --headless --import || true
 
       - name: Prepare output dir
         run: mkdir -p releases/android