SCons: Improve cache purging logic

• Implement caching via SCons arguments, rather than environment variables

.github/actions/godot-build/action.yml

@@ -18,12 +18,12 @@ inputs:
     required: false
   scons-cache:
     description: The SCons cache path.
-    default: ${{ github.workspace }}/.scons-cache/
+    default: ${{ github.workspace }}/.scons_cache/
   scons-cache-limit:
     description: The SCons cache size limit.
     # actions/cache has 10 GiB limit, and GitHub runners have a 14 GiB disk.
     # Limit to 7 GiB to avoid having the extracted cache fill the disk.
-    default: 7168
+    default: 7
 
 runs:
   using: composite
@@ -32,10 +32,8 @@ runs:
       shell: sh
       env:
         SCONSFLAGS: ${{ inputs.sconsflags }}
-        SCONS_CACHE: ${{ inputs.scons-cache }}
-        SCONS_CACHE_LIMIT: ${{ inputs.scons-cache-limit }}
       run: |
-        echo "Building with flags:" platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }}
+        echo "Building with flags:" platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }} "cache_path=${{ inputs.scons-cache }}" cache_limit=${{ inputs.scons-cache-limit }}
 
         if [ "${{ inputs.target }}" != "editor" ]; then
           # Ensure we don't include editor code in export template builds.
@@ -49,5 +47,5 @@ runs:
           export BUILD_NAME="gh"
         fi
 
-        scons platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }}
+        scons platform=${{ inputs.platform }} target=${{ inputs.target }} tests=${{ inputs.tests }} ${{ env.SCONSFLAGS }} "cache_path=${{ inputs.scons-cache }}" cache_limit=${{ inputs.scons-cache-limit }}
         ls -l bin/

.github/actions/godot-cache-restore/action.yml

@@ -6,7 +6,7 @@ inputs:
     default: ${{ github.job }}
   scons-cache:
     description: The SCons cache path.
-    default: ${{ github.workspace }}/.scons-cache/
+    default: ${{ github.workspace }}/.scons_cache/
 
 runs:
   using: composite
@@ -29,7 +29,6 @@ runs:
         #   4. A partial match for the same base branch only (not ideal, matches any PR with the same base branch).
 
         restore-keys: |
-          ${{ inputs.cache-name }}-${{ env.GODOT_BASE_BRANCH }}-${{ github.ref }}-${{ github.sha }}
           ${{ inputs.cache-name }}-${{ env.GODOT_BASE_BRANCH }}-${{ github.ref }}
           ${{ inputs.cache-name }}-${{ env.GODOT_BASE_BRANCH }}-refs/heads/${{ env.GODOT_BASE_BRANCH }}
           ${{ inputs.cache-name }}-${{ env.GODOT_BASE_BRANCH }}

.github/actions/godot-cache-save/action.yml

@@ -6,7 +6,7 @@ inputs:
     default: ${{ github.job }}
   scons-cache:
     description: The SCons cache path.
-    default: ${{ github.workspace }}/.scons-cache/
+    default: ${{ github.workspace }}/.scons_cache/
 
 runs:
   using: composite

.github/workflows/godot_cpp_test.yml

@@ -52,9 +52,6 @@ jobs:
       #   continue-on-error: true
 
       - name: Build godot-cpp test extension
-        env: # Keep synced with godot-build.
-          SCONS_CACHE: ${{ github.workspace }}/.scons-cache/
-          SCONS_CACHE_LIMIT: 7168
         run: scons --directory=./godot-cpp/test target=template_debug dev_build=yes verbose=yes
 
       # - name: Save Godot build cache