Unify the Godot 4.7.2 CI environment and cache it

Update project features and CI installs/templates to Godot 4.7.2, remove the
old version matrix, and cache the Godot binary and export templates with Gitea
Actions cache. Update release/docs/version references accordingly. Project
import and headless tests pass locally under 4.7.2.

.gitea/workflows/build.yml

@@ -7,6 +7,10 @@ on:
   pull_request:
   workflow_dispatch:
 
+env:
+  GODOT_VERSION: "4.7.2"
+  GODOT_BIN: /usr/local/bin/godot
+
 jobs:
   checks:
     name: Import + headless tests
@@ -17,12 +21,23 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install Godot 4.3
+      - name: Restore Godot binary cache
+        uses: actions/cache@v4
+        with:
+          path: /usr/local/bin/godot
+          key: godot-${{ runner.os }}-${{ env.GODOT_VERSION }}-v1
+
+      - name: Install Godot 4.7.2
         run: |
+          if [ -x /usr/local/bin/godot ]; then
+            godot --version
+            exit 0
+          fi
           curl -sL -o /tmp/godot.zip \
-            https://github.com/godotengine/godot/releases/download/4.3-stable/Godot_v4.3-stable_linux.x86_64.zip
+            https://github.com/godotengine/godot/releases/download/4.7.2-stable/Godot_v4.7.2-stable_linux.x86_64.zip
           unzip -qo /tmp/godot.zip -d /tmp/godot-bin
-          sudo install /tmp/godot-bin/Godot_v4.3-stable_linux.x86_64 /usr/local/bin/godot
+          sudo install /tmp/godot-bin/Godot_v4.7.2-stable_linux.x86_64 /usr/local/bin/godot
+          godot --version
 
       - name: Import project (build class cache)
         run: godot --headless --import
@@ -56,18 +71,38 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install Godot 4.3 and export templates
+      - name: Restore Godot binary cache
+        uses: actions/cache@v4
+        with:
+          path: /usr/local/bin/godot
+          key: godot-${{ runner.os }}-${{ env.GODOT_VERSION }}-v1
+
+      - name: Restore export templates cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.local/share/godot/export_templates/4.7.2.stable
+          key: godot-templates-${{ runner.os }}-${{ env.GODOT_VERSION }}-v1
+
+      - name: Install Godot 4.7.2 and export templates
         run: |
-          curl -sL -o /tmp/godot.zip \
-            https://github.com/godotengine/godot/releases/download/4.3-stable/Godot_v4.3-stable_linux.x86_64.zip
-          unzip -qo /tmp/godot.zip -d /tmp/godot-bin
-          sudo install /tmp/godot-bin/Godot_v4.3-stable_linux.x86_64 /usr/local/bin/godot
+          if [ ! -x /usr/local/bin/godot ]; then
+            curl -sL -o /tmp/godot.zip \
+              https://github.com/godotengine/godot/releases/download/4.7.2-stable/Godot_v4.7.2-stable_linux.x86_64.zip
+            unzip -qo /tmp/godot.zip -d /tmp/godot-bin
+            sudo install /tmp/godot-bin/Godot_v4.7.2-stable_linux.x86_64 /usr/local/bin/godot
+          fi
+          godot --version
+          if [ -f "$HOME/.local/share/godot/export_templates/4.7.2.stable/linux_release.x86_64" ]; then
+            ls "$HOME/.local/share/godot/export_templates/4.7.2.stable" | head -5
+            exit 0
+          fi
           curl -sL -o /tmp/templates.tpz \
-            https://github.com/godotengine/godot/releases/download/4.3-stable/Godot_v4.3-stable_export_templates.tpz
-          mkdir -p ~/.local/share/godot/export_templates/4.3.stable
-          cd /tmp && rm -rf tpl && mkdir tpl && unzip -qo templates.tpz -d tpl
-          cp tpl/templates/* "$HOME/.local/share/godot/export_templates/4.3.stable/" 2>/dev/null || true
-          ls "$HOME/.local/share/godot/export_templates/4.3.stable" | head -5
+            https://github.com/godotengine/godot/releases/download/4.7.2-stable/Godot_v4.7.2-stable_export_templates.tpz
+          rm -rf /tmp/tpl && mkdir -p /tmp/tpl
+          unzip -qo /tmp/templates.tpz -d /tmp/tpl
+          mkdir -p "$HOME/.local/share/godot/export_templates/4.7.2.stable"
+          cp /tmp/tpl/templates/* "$HOME/.local/share/godot/export_templates/4.7.2.stable/"
+          ls "$HOME/.local/share/godot/export_templates/4.7.2.stable" | head -5
 
       - name: Import project
         run: godot --headless --import
@@ -114,7 +149,7 @@ jobs:
         if: startsWith(github.ref, 'refs/tags/')
         env:
           # An explicit repo secret wins. Without one, publish_release.sh reuses
-          # the local git extraheader that actions/checkout configures for the job
+          # the local git extraheader that actions/checkout configures on the job
           # (the runner's own credentials), so tag builds still publish.
           GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
           VERSION: ${{ github.ref_name }}