fix: remove broken tests based on jetty-runner (#354)

* tests based on jetty-runner do not work because
  the jetty-runner JAR contains invalid Java SPI services config files
* due to these invalid files Jetty 11.0.20+ is unable to properly
  initialize itself itself
* This change removes all tests based on jetty-runner
  and bumps the Jetty version to 11.0.24
* There are already jobs using the Jetty Maven plugin to
  launch a testing instance + run all tests

.github/workflows/tests.yml

@@ -35,42 +35,6 @@ jobs:
           path: target/plantuml.war
           retention-days: 1
 
-  test-java-8-war:
-    runs-on: ubuntu-latest
-    needs: test-java-8-war-generation
-    strategy:
-      matrix:
-        java-version: [ 11, 17 ]
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0
-
-      - name: retrieve generated files (jre8)
-        uses: actions/download-artifact@v4.1.7
-        with:
-          name: war-jre8
-          path: artifacts
-
-      - uses: actions/setup-java@v3
-        with:
-          distribution: "zulu"
-          java-version: ${{ matrix.java-version }}
-          check-latest: true
-          cache: "maven"
-
-      - name: Prepare jetty-runner tests
-        run: mvn --batch-mode clean package
-
-      - name: Start jetty server over jetty-runner
-        run: java -jar target/dependency/jetty-runner.jar --config src/main/config/jetty.xml --path /plantuml artifacts/plantuml.war &
-
-      - name: Wait 5 seconds (to let jetty-runner start the jetty server)
-        run: sleep 5s
-
-      - name: Run tests against "mvn jetty:run" server
-        run: mvn --batch-mode test -DskipTests=false -Dgroups=\!graphviz-test -DargLine="-Dsystem.test.server=http://localhost:8080/plantuml"
-
   test-mvn-livecycle:
     runs-on: ubuntu-latest
     strategy:
@@ -163,36 +127,6 @@ jobs:
       - name: Run tests against "mvn jetty:run" server
         run: mvn --batch-mode test -DskipTests=false -Dgroups=\!graphviz-test -DargLine="-Dsystem.test.server=http://localhost:8080/plantuml"
 
-  test-jetty-runner:
-    runs-on: ubuntu-latest
-    needs: test-mvn-livecycle
-    strategy:
-      matrix:
-        java-version: [ 11, 17 ]
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0
-
-      - uses: actions/setup-java@v3
-        with:
-          distribution: "zulu"
-          java-version: ${{ matrix.java-version }}
-          check-latest: true
-          cache: "maven"
-
-      - name: Prepare jetty-runner tests
-        run: mvn --batch-mode clean package
-
-      - name: Start jetty server over jetty-runner
-        run: java -jar target/dependency/jetty-runner.jar --config src/main/config/jetty.xml --path /plantuml target/plantuml.war &
-
-      - name: Wait 5 seconds (to let jetty-runner start the jetty server)
-        run: sleep 5s
-
-      - name: Run tests against "mvn jetty:run" server
-        run: mvn --batch-mode test -DskipTests=false -Dgroups=\!graphviz-test -DargLine="-Dsystem.test.server=http://localhost:8080/plantuml"
-
   test-jetty:
     runs-on: ubuntu-latest
     needs: test-mvn-livecycle