docs: add v3.0.3 ~and v3.1.0~ changelog updates. (#6023)

git amend: v3.1.0 section removed

* [skip ci] docs: add v3.0.3 and v3.1.0 changelog updates.

Made-with: Cursor

* [skip ci] docs: set v3.0.3 release date: March 31, 2026
1 file changed