Remove outdated TODO comments for contrib 1.50.0 update

- Remove TODO comments about updating to contrib 1.50.0
- Remove duplicate GCP resource version.properties handling
- Project is already using OpenTelemetry API 1.50.0 as evidenced in:
  - instrumentation/opentelemetry-api/opentelemetry-api-1.50/
  - opentelemetry-api-shaded-for-instrumenting uses 1.50.0-alpha

These TODO items are no longer relevant and the duplicate
configuration was causing unnecessary complexity in the build.

Author: hoteye

javaagent/build.gradle.kts

@@ -161,10 +161,6 @@ tasks {
     excludeBootstrapClasses()
 
     duplicatesStrategy = DuplicatesStrategy.FAIL
-    // TODO: remove after updating contrib to 1.50.0
-    filesMatching("io/opentelemetry/contrib/gcp/resource/version.properties") {
-      duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-    }
     exclude("META-INF/LICENSE")
     exclude("META-INF/NOTICE")
     exclude("META-INF/maven/**")
@@ -190,10 +186,6 @@ tasks {
     exclude("okhttp3/internal/publicsuffix/PublicSuffixDatabase.list")
 
     duplicatesStrategy = DuplicatesStrategy.FAIL
-    // TODO: remove after updating contrib to 1.50.0
-    filesMatching("io/opentelemetry/contrib/gcp/resource/version.properties") {
-      duplicatesStrategy = DuplicatesStrategy.EXCLUDE
-    }
     filesMatching("META-INF/io/opentelemetry/instrumentation/**") {
       duplicatesStrategy = DuplicatesStrategy.EXCLUDE
     }