Updating the HEAD Release log for 0.26.3 release

PiperOrigin-RevId: 364912677

Author: dhruvesh09

RELEASE.md

@@ -185,6 +185,39 @@
 
 *   N/A
 
+# Version 0.26.3
+
+*   This a bug fix only version.
+
+## Major Features and Improvements
+
+*   N/A
+
+## Breaking changes
+
+*   N/A
+
+### For pipeline authors
+
+*   N/A
+
+### For component authors
+
+*   N/A
+
+## Deprecations
+
+*   N/A
+
+## Bug fixes and other changes
+
+*   Automatic autoreload of underlying modules a single `_ModuleFinder`
+    registered per module.
+
+## Documentation updates
+
+*   N/A
+
 # Version 0.26.1
 
 *   This a bug fix only version