ci : only save openvino caches on github-hosted master (ggml-org#20593)

* only save openvino ccache on master

* disable toolkit cache if self-hosted

* only cache on github-hosted runners

* remove toolkit cache [no ci]

Author: CISC

.github/workflows/build-self-hosted.yml

@@ -222,15 +222,7 @@ jobs:
         id: checkout
         uses: actions/checkout@v6
 
-      - name: Use OpenVINO Toolkit Cache
-        uses: actions/cache@v5
-        id: cache-openvino
-        with:
-          path: ./openvino_toolkit
-          key: openvino-toolkit-v${{ env.OPENVINO_VERSION_FULL }}-${{ runner.os }}
-
       - name: Setup OpenVINO Toolkit
-        if: steps.cache-openvino.outputs.cache-hit != 'true'
         uses: ./.github/actions/linux-setup-openvino
         with:
           path: ./openvino_toolkit

.github/workflows/build.yml

@@ -604,10 +604,12 @@ jobs:
           uses: actions/checkout@v6
 
         - name: ccache
+          if: runner.environment == 'github-hosted'
           uses: ggml-org/ccache-action@v1.2.16
           with:
             key: ubuntu-24-openvino-${{ matrix.variant }}-no-preset-v1
             evict-old-files: 1d
+            save: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
 
         - name: Dependencies
           id: depends
@@ -617,6 +619,7 @@ jobs:
             sudo apt-get install -y ocl-icd-opencl-dev opencl-headers opencl-clhpp-headers intel-opencl-icd
 
         - name: Use OpenVINO Toolkit Cache
+          if: runner.environment == 'github-hosted'
           uses: actions/cache@v5
           id: cache-openvino
           with: