Adding the ability to get the NX_BASE after commits with [skip-ci] type messages

[eXigentCoder]

In our workflow, we use @jscutlery/semver to calculate and set the version numbers for our NPM packages in their package.json files in our NX monorepo and commit that back to the GitHub repositiory with a [skip-ci] message as follows:

Since the package.json files will have been changed, this causes the nx-set-shas action to always include each and every one of those NX projects in the affected command which essentially causes a loop. In the above screenshot, the user commits are in green and you can see each package gets published and tagged each time.

This change allows the user to specify if the NX_BASE should be calculated as the last SHA that contains a [skip-ci] message after the originally calculated NX_BASE

[daltonmcphaden]

LGTM. This is something I also need. Can we get a maintainer to release this?

[yann510]

This would also benefit us @AgentEnder could we please get a review :)