Specify detect-secrets version to be used

[javierjulio]

It would help to have the capability to specify the version of detect-secrets that should be installed to avoid surprise errors on runs where the version changed due to a new release. Since detect-secrets is installed with pip, it is possible to specify the version using the pip install command.

If it could work like the version support in action-rubocop where it uses the version from a lock file that would be ideal. This way another automated tool like Dependabot picks up the version change and isolates that to a new PR running the newer version of detect-secrets.