fix: update macOS version in CI matrix to include macos-15 (#345)

Signed-off-by: Gordon Smith <[email protected]>

Author: GordonSmith

.github/workflows/test-pr.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-24.04, macos-13, macos-14]
+        os: [ubuntu-24.04, macos-14, macos-15]
         node: [22, 24]
 
     runs-on: ${{ matrix.os }}