hmac: disable minimal-versions because of pre-releases

Author: baloo

.github/workflows/hmac.yml

@@ -39,6 +39,7 @@ jobs:
       - run: cargo build --no-default-features --release --target ${{ matrix.target }}
 
   minimal-versions:
+    if: false # TODO: temp disabled due to unpublished prerelease dependencies
     uses: RustCrypto/actions/.github/workflows/minimal-versions.yml@master
     with:
       working-directory: ${{ github.workflow }}