CI: Update to actions/cache@v3, increase cache limit to 10 GiB

And force rebuild of Linux cache which got corrupted...

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

@@ -20,7 +20,8 @@ inputs:
     default: "${{ github.workspace }}/.scons-cache/"
   scons-cache-limit:
     description: The scons cache size limit.
-    default: 4096
+    # actions/cache has 10 GiB limit. Allow 10 GiB minus 256 MiB.
+    default: 9984
 runs:
   using: "composite"
   steps:

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

@@ -12,7 +12,7 @@ runs:
   steps:
     # Upload cache on completion and check it out now
     - name: Load .scons_cache directory
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         path: ${{inputs.scons-cache}}
         key: ${{inputs.cache-name}}-${{env.GODOT_BASE_BRANCH}}-${{github.ref}}-${{github.sha}}