Make ci job not run on macos-latest (2nd attempt)

The `macos-latest`(14.4.1) does not have java8.
https://github.com/actions/runner-images/blob/main/images/macos/macos-144-arm64-Readme.md

Comment out `macos-latest` matrix.

.github/workflows/ci.yml

@@ -10,16 +10,18 @@ on:
 jobs:
   build:
     if: github.repository == 'r2dbc/r2dbc-proxy'
-    runs-on: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
     strategy:
         matrix:
             include:
                 - os: ubuntu-latest
                   mvn: ./mvnw
                 - os: windows-latest
                   mvn: mvn
-                - os: macos-latest
-                  mvn: ./mvnw
+               # Since macOS 14.4.1, macos-latest does not have java 8.
+               # https://github.com/actions/runner-images/blob/main/images/macos/macos-144-arm64-Readme.md
+               # - os: macos-latest
+               #   mvn: ./mvnw
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK 1.8