Java: Add release notes for release 5.30.0 (#2452)

* Add new release notes

* fix: Changes from lint

* 30 to 44

---------

Co-authored-by: SAP Cloud SDK Bot <cloudsdk@sap.com>
Co-authored-by: sap-cloud-sdk-bot[bot] <274190970+sap-cloud-sdk-bot[bot]@users.noreply.github.com>
Co-authored-by: Roshin Rajan Panackal <roshin.rajan.panackal@sap.com>

Author: 3 people

docs-java/release-notes/index.jsx

@@ -1,6 +1,7 @@
 import React from 'react';
 import Notes0To14 from './release-notes-0-to-14.mdx';
 import Notes15To29 from './release-notes-15-to-29.mdx';
+import Notes30To44 from './release-notes-30-to-44.mdx';
 
 export function ReleaseNotes0To14() {
   return <Notes0To14 />;
@@ -9,3 +10,7 @@ export function ReleaseNotes0To14() {
 export function ReleaseNotes15To29() {
   return <Notes15To29 />;
 }
+
+export function ReleaseNotes30To44() {
+  return <Notes30To44 />;
+}

docs-java/release-notes/release-notes-30-to-44.mdx

@@ -0,0 +1,20 @@
+## 5.30.0 - May 06, 2026
+
+[All Release Changes](https://github.com/SAP/cloud-sdk-java/releases/tag/rel%2F5.30.0)
+
+### 🚧 Known Issues
+
+-
+
+### 🔧 Compatibility Notes
+
+- [OpenAPI] In Apache HttpClient generator, file upload parameters are now pinned to type `java.io.File`, unmodifiable with `<typeMappings>` in generator configuration.
+
+### ✨ New Functionality
+
+-
+
+### 📈 Improvements
+
+- Enable Retry behavior for HttpClient5 instances, to mirror legacy behvior for HttpClient4: `1` retry with `1s` delay
+  for response codes `429` (Too Many Requests) and `503` (Service Unavailable).