upgrade gradle, fix implicit task dependency, and fix java targeting (#111)

Author: andrewparmet

build.gradle.kts

@@ -72,4 +72,9 @@ subprojects {
             }
         }
     }
+
+    configure<JavaPluginExtension> {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
 }

buildSrc/src/main/kotlin/RemotePublishing.kt

@@ -110,6 +110,14 @@ fun Project.enablePublishing(defaultJars: Boolean = true) {
             withSourcesJar()
         }
 
+        afterEvaluate {
+            if (tasks.findByName("generateProto") != null) {
+                tasks.named("sourcesJar").configure {
+                    dependsOn("generateProto")
+                }
+            }
+        }
+
         tasks.register<Jar>("javadocJar") {
             from("$rootDir/README.md")
             archiveClassifier.set("javadoc")

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists