ci(sdk): Ensure we append new release to the chaneglog instead of overwriting it. (#43729)

* Mock that the changelog is different from the one in master

* Apply changelog patch incase the changelog is created from another branch

* Dry run npm publish so I could test

* Fix failed patch

* Speed up testing by not building jar

* Fix adding new changelog to master

* feat(sdk): A placeholder for an actual feature in the changelog

* Mock that the changelog diverges from master

* Revert "Speed up testing by not building jar"

This reverts commit acb80d74.

* Revert "Dry run npm publish so I could test"

This reverts commit f4e679ef.

* Revert "Mock that the changelog diverges from master"

This reverts commit 0e77a68e.