Update release date and add HTTP compression features

Updated release date and added HTTP compression support.

Author: lalitb

opentelemetry-otlp/CHANGELOG.md

@@ -4,7 +4,7 @@
 
 ## 0.30.1
 
-Released 2025-Jan-06
+Released 2025-Sep-11
 
 - Update `opentelemetry-proto` dependency version to 0.30.1
 - Add HTTP compression support with `gzip-http` and `zstd-http` feature flags