feat: automate releases using script

[milinddethe15]

What this PR does / why we need it:

1. This PR adds a release script to generate a releasing commit of vX.Y.Z

Usage to generate for new release:

./hack/release.sh X.Y.Z

• It updates the VERSION file
• and, the image tags in manifest to correspond to that particaluar version

2. Adds a release github action

• publishes the image with the corresponding version tag

Testing on forked branch: https://github.com/milinddethe15/kf-trainer/tree/release-5.0.0

Which issue(s) this PR fixes (optional, in Fixes #<issue number>, #<issue number>, ... format, will close the issue(s) when PR gets merged):
Fixes #2155

Checklist:

• Docs included if any changes are user facing

[google-oss-prow]

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[coveralls]

Pull Request Test Coverage Report for Build 14912026962

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 28.807%

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Totals
Change from base Build 14890359838:	0.0%
Covered Lines:	840
Relevant Lines:	2916

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💛 - Coveralls

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[kramaranya]

/remove-lifecycle stale

[andreyvelich]

Hi @milinddethe15, since we release the v2.0.0, do you want to finalize this release automation work for the future releases (e.g. v2.1)?

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.