fix(deps): update dependency org.codehaus.groovy:groovy-bom to v3.0.21 (main) (#10732)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

conventions/src/main/kotlin/otel.java-conventions.gradle.kts

@@ -140,7 +140,7 @@ dependencies {
   compileOnly("com.google.errorprone:error_prone_annotations")
 
   codenarc("org.codenarc:CodeNarc:3.4.0")
-  codenarc(platform("org.codehaus.groovy:groovy-bom:3.0.20"))
+  codenarc(platform("org.codehaus.groovy:groovy-bom:3.0.21"))
 
   modules {
     // checkstyle uses the very old google-collections which causes Java 9 module conflict with