Add ci for jdk21 runtime (#1265)

* add ci for jdk 21

* update gradle 8.4

---------

Co-authored-by: 致节 <[email protected]>

Author: HzjNeverStop

.github/workflows/maven.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        jdk: [17]
+        jdk: [17, 21]
     steps:
     - uses: actions/checkout@v2
     - name: Set up JDK

sofa-boot-project/sofa-boot-tools/sofa-boot-gradle-plugin/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists