Excavator: Use baseline-java-versions to manage Java versions

.circleci/template.sh

@@ -1,5 +1,3 @@
 #!/usr/bin/env bash
 export CIRCLECI_TEMPLATE=java-library-oss
 export JDK=17
-export UNIT_TEST_11=true
-export UNIT_TEST_15=true

build.gradle

@@ -29,6 +29,7 @@ apply plugin: 'com.palantir.failure-reports'
 apply plugin: 'com.palantir.git-version'
 apply plugin: 'com.palantir.baseline'
 apply plugin: 'com.palantir.consistent-versions'
+apply plugin: 'com.palantir.baseline-java-versions'
 
 version System.env.CIRCLE_TAG ?: gitVersion()
 
@@ -48,8 +49,6 @@ subprojects {
     apply plugin: 'java-library'
     apply plugin: 'org.inferred.processors'
 
-    sourceCompatibility = 11
-    targetCompatibility = 11
 
     tasks.withType(Checkstyle).configureEach {
         enabled = false
@@ -94,3 +93,7 @@ idea.project.ipr.withXml { xml ->
     </component>
     '''))
 }
+
+javaVersions {
+    libraryTarget = 11
+}