Fix the SourceSet.projectDefault() extension adding sources to resources

The `include` calls were effectively made on the `resources`
`SourceDirectorySet`, which meant including '**' from 'src' as well.

Since the 'SourceDirectorySet' API is quite limited and does not support
specifying includes/excludes separately, configure the
`ProcessResources` task instead.

compiler/util/build.gradle.kts

@@ -17,7 +17,7 @@ dependencies {
 sourceSets {
     "main" {
         projectDefault()
-        resources.srcDir(File(rootDir, "resources")).apply { include("**") }
+        resources.srcDir(File(rootDir, "resources"))
     }
     "test" {}
 }