CI-unixish-docker.yml: fixate hendrikmuhs/ccache-action on 1.2.11 to fix older images (#5918)

See

https://github.com/danmar/cppcheck/actions/runs/7677304162/job/20926809147?pr=5917
hendrikmuhs/ccache-action#178

Author: firewave

.github/workflows/CI-unixish-docker.yml

@@ -53,8 +53,10 @@ jobs:
       # needs to be called after the package installation since
       # - it doesn't call "apt-get update"
       # - it doesn't support centos
+      #
+      # needs to be to fixated on 1.2.11 so it works with older images - see https://github.com/hendrikmuhs/ccache-action/issues/178
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2
+        uses: hendrikmuhs/ccache-action@v1.2.11
         with:
           key: ${{ github.workflow }}-${{ matrix.image }}
 
@@ -110,8 +112,10 @@ jobs:
       # needs to be called after the package installation since
       # - it doesn't call "apt-get update"
       # - it doesn't support centos
+      #
+      # needs to be to fixated on 1.2.11 so it works with older images - see https://github.com/hendrikmuhs/ccache-action/issues/178
       - name: ccache
-        uses: hendrikmuhs/ccache-action@v1.2
+        uses: hendrikmuhs/ccache-action@v1.2.11
         with:
           key: ${{ github.workflow }}-${{ matrix.image }}