update defaults for branch from master to main

[tkishel]

Describe the issue

Given that the default branch name has changed from master to main:

https://github.com/github/renaming

Should the default for --branch be changed as well?

https://github.com/bridgecrewio/checkov/blob/master/checkov/main.py#L347

[nimrodkor]

Sounds good to me. Want to contribute that change?

[tkishel]

I don't have enough of an understanding of the potential impact of this change to the internal workflows of the project (aka: I know enough to be dangerous ) and have not set up all of the testing in the CONTRIBUTING document. So, yes, but not yet. Also, this may be a change to hold back for the next major or minor release, rather than a patch?

[stale[bot]]

Thanks for contributing to Checkov! We've automatically marked this issue as stale to keep our issues list tidy, because it has not had any activity for 6 months. It will be closed in 14 days if no further activity occurs. Commenting on this issue will remove the stale tag. If you want to talk through the issue or help us understand the priority and context, feel free to add a comment or join us in the Checkov slack channel at https://slack.bridgecrew.io Thanks!

[stale[bot]]

Closing issue due to inactivity. If you feel this is in error, please re-open, or reach out to the community via slack: https://slack.bridgecrew.io Thanks!