Always cleanup node in Maven check jobs

The JDK 22 job started failing recently in the post-setup step with a
`System.IO.IOException: No space left on device` error.

.github/workflows/ci.yml

@@ -56,8 +56,8 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { java-version: 22, cache: 'true', cleanup-node: false }
-          - { java-version: 23-ea, cache: 'restore', cleanup-node: true }
+          - { java-version: 22, cache: 'true' }
+          - { java-version: 23-ea, cache: 'restore' }
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@v4
@@ -72,7 +72,7 @@ jobs:
         with:
           cache: ${{ matrix.cache }}
           java-version: ${{ matrix.java-version }}
-          cleanup-node: ${{ matrix.cleanup-node }}
+          cleanup-node: true
       - name: Check SPI backward compatibility
         run: |
           export MAVEN_OPTS="${MAVEN_INSTALL_OPTS}"