Bring back some of Till's cache changes

Signed-off-by: itowlson <[email protected]>

Author: itowlson

.github/actions/spin-ci-dependencies/action.yml

@@ -114,6 +114,7 @@ runs:
       if: ${{ inputs.rust-cache == 'true' }}
       with:
         shared-key: "${{ runner.os }}-full-${{ hashFiles('./Cargo.lock', './os-release') }}"
+        save-if: ${{ github.ref == 'refs/heads/main' }}
 
     ## Install nomad
     - name: Install nomad

.github/workflows/build.yml

@@ -99,7 +99,6 @@ jobs:
         with:
           rust: true
           rust-cross: true
-          rust-cache: true
 
       - name: Cargo Build
         run: cross build --target ${{ matrix.config.target }} --release --features openssl/vendored