build.gradle: remove sourceCompatibility, targetCompatibility

We have defined `release` one way or another, and on JDK 17 that should
suffice.

core/build.gradle

@@ -37,8 +37,6 @@ if (GradleVersion.current().compareTo(gradleVersionTargetJVM) > 0) {
     }
 }
 
-sourceCompatibility = 8
-targetCompatibility = 8
 tasks.withType(JavaCompile) {
     options.compilerArgs.addAll(['--release', '8'])
     options.compilerArgs << '-Xlint:deprecation'

examples-kotlin/build.gradle

@@ -11,7 +11,6 @@ compileKotlin {
     }
 }
 
-sourceCompatibility = 17
 tasks.withType(JavaCompile) {
     options.encoding = 'UTF-8'
     options.release = 17

examples/build.gradle

@@ -8,7 +8,6 @@ dependencies {
     implementation 'org.slf4j:slf4j-jdk14:2.0.13'
 }
 
-sourceCompatibility = 17
 tasks.withType(JavaCompile) {
     options.encoding = 'UTF-8'
     options.compilerArgs.addAll(['--release', '17'])

integration-test/build.gradle

@@ -18,7 +18,6 @@ dependencies {
     testRuntimeOnly "org.junit.vintage:junit-vintage-engine:5.10.3"
 }
 
-sourceCompatibility = 17
 tasks.withType(JavaCompile) {
     options.encoding = 'UTF-8'
     options.release = 17

tools/build.gradle

@@ -8,7 +8,6 @@ dependencies {
     implementation 'org.slf4j:slf4j-jdk14:2.0.13'
 }
 
-sourceCompatibility = 17
 tasks.withType(JavaCompile) {
     options.compilerArgs.addAll(['--release', '17'])
     options.compilerArgs << '-Xlint:deprecation'

wallettemplate/build.gradle

@@ -20,7 +20,6 @@ javafx {
     modules = [ 'javafx.controls', 'javafx.fxml' ]
 }
 
-sourceCompatibility = 17
 tasks.withType(JavaCompile) {
     options.encoding = 'UTF-8'
     options.release = 17

wallettool/build.gradle

@@ -31,7 +31,6 @@ dependencies {
     testImplementation 'org.slf4j:slf4j-jdk14:2.0.13'
 }
 
-sourceCompatibility = 17
 tasks.withType(JavaCompile) {
     options.compilerArgs.addAll(['--release', '17'])
     options.compilerArgs << '-Xlint:deprecation'