[ci] Disable ccache.

Disable ccache for now because caching (2 min) is slower than building itself (20 s).

.github/workflows/build.yml

@@ -22,9 +22,10 @@ jobs:
     steps:
     - uses: actions/checkout@v4
 
-    # Set up ccache
-    - name: ccache
-      uses: hendrikmuhs/[email protected]
+    # Note: this is currently disabled because caching is slower than building itself.
+    # # Set up ccache
+    # - name: ccache
+    #   uses: hendrikmuhs/[email protected]
 
     # Install CMake
     - uses: lukka/get-cmake@latest