ci: fix updatecli workflow for prereleases

[dottorblaster]

Right now what we have for prereleases is:

• We tag a prerelease
• The release is correctly drafted and published
• updatecli opens a PR with the helm chart bump
• We close the helm chart bump PR
• We do an actual stable release
• updatecli isn't able to create another helm chart bump

We should address this before releasing another RC or beta version.

Acceptance criteria

• We can release a prerelease version without worrying about helm chart bumps
• Helm chart bumps on stable releases can be created correctly after a number of betas or RCs