refactor: 💡 Drop support for java 8

BREAKING CHANGE: 🧨 Dropped support for java 8

.github/workflows/maven-build.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [ '8', '11' ]
+        java: [ '11' ]
     steps:
       - uses: actions/checkout@v2
       - name: Set up JDK ${{ matrix.java }}

perun-oidc-server-webapp/pom.xml

@@ -98,10 +98,6 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
-				<configuration>
-					<source>${java-version}</source>
-					<target>${java-version}</target>
-				</configuration>
 			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>

pom.xml

@@ -118,9 +118,9 @@
 		<aspectjweaver.version>1.9.7</aspectjweaver.version>
 
 		<!-- BUILD -->
-		<java-version>8</java-version>
+		<java.version>11</java.version>
-		<maven.compiler.source>${java-version}</maven.compiler.source>
+		<maven.compiler.source>${java.version}</maven.compiler.source>
-		<maven.compiler.target>${java-version}</maven.compiler.target>
+		<maven.compiler.target>${java.version}</maven.compiler.target>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 	</properties>
@@ -367,8 +367,8 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-compiler-plugin</artifactId>
 				<configuration>
-					<source>${java-version}</source>
+					<source>${java.version}</source>
-					<target>${java-version}</target>
+					<target>${java.version}</target>
 				</configuration>
 			</plugin>
 		</plugins>