ci: Increase ccache size

Increase the size limit of ccache to 2G. Otherwise the larger
compiles will not take advantage of the cache.

Signed-off-by: Christian A. Ehrhardt <[email protected]>

Author: Christian A. Ehrhardt

.github/workflows/build.yml

@@ -127,6 +127,7 @@ jobs:
         uses: hendrikmuhs/[email protected]
         with:
           key: kbuild-${{ matrix.arch }}-${{ matrix.compiler }}
+          max-size: 2G
 
       - name: Build Kernel
         shell: bash