Make optional "Skip if there are no new commits in pre-release re runs"

[druskus20]

Motivation:

The behaviour I want is to force a tag bump even if there are no changes - in order to keep versions matching with other apps / deployments.

As I understand this is the default behavior. However I am using a separate release action. This means that I am forced to run github-tag-action in pre-release mode.

Solution

As I understand, putting the checks implemented in #234 behind a parameter should be enough - such as "SKIP_NO_COMMITS_PRERELEASE"

[sbe-arg]

Thanks for opening #310 although if we merge it we cannot release it atm.