Switch to Biome for JSON formatting (#7967)

Replaces the previous Prettier step which required a separate
installation of npm to work at all. Biome no longer requires any extra
dependencies as Spotless will simply grab a static binary to use from
within `mavenLocal`.

~~Note that the `biome()` step also adds the `mavenLocal()` repository
definition to the buildscript, which causes the project build to fail
when using `RepositoriesMode.FAIL_ON_PROJECT_REPOS` in the settings
file.~~

---------

Co-authored-by: Sebastian Hartte <shartte@users.noreply.github.com>

build.gradle

@@ -65,6 +65,7 @@ configurations {
 }
 
 import appengbuild.*
+import com.diffplug.gradle.spotless.JsonExtension
 
 dependencies {
     // To be copied into the jar file
@@ -411,14 +412,23 @@ spotless {
             if (it.contains('*;\n')) {
                 throw new Error('No wildcard imports allowed')
             }
+
+            it
         }
         bumpThisNumberIfACustomStepChanges(1)
     }
 
-    format 'json', {
+   json {
         target 'src/*/resources/**/*.json'
         targetExclude 'src/generated/resources/**'
-        prettier().config(['parser': 'json'])
+        var biomeConfig = it.new JsonExtension.BiomeJson(null)
+        try {
+            biomeConfig.downloadDir(new File(rootDir, ".gradle/biome").absolutePath)
+        } catch (Exception ignored) {
+        }
+        addStep(biomeConfig.createStep())
+        indentWithSpaces(2)
+        endWithNewline()
     }
 }
 

settings.gradle

@@ -20,7 +20,6 @@ dependencyResolutionManagement {
     repositoriesMode = RepositoriesMode.FAIL_ON_PROJECT_REPOS
     rulesMode = RulesMode.FAIL_ON_PROJECT_RULES
     repositories {
-        mavenLocal()
         maven {
             url "https://maven.shedaniel.me/"
             content {