Exclude check-license workflows for non-Linux

We now have a matrix job to ensure test coverage on all supported OS
platforms. This also causes the `check-license` job to run on each OS.

The license check isn't platform specific, so this ends up being a
little wasteful. This adds an exclude block to skip macOS and Windows
since they are not needed and those particular OS's take longer to run
than Linux.

Signed-off-by: Sean McGinnis <[email protected]>

.github/workflows/rust.yml

@@ -17,6 +17,11 @@ jobs:
       matrix:
         make_target: ["check-licenses", "build", "integ"]
         os: [ubuntu-latest, windows-latest, macos-latest]
+        exclude:
+          - os: windows-latest
+            make_target: check-licenses
+          - os: macos-latest
+            make_target: check-licenses
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4