User must provide either --git-branch or --git-tag when creating a workload using --git-commit flag

[heyjcollins]

Description of problem

While researching an issue whereby a user is required to provide --git-branch in addition to --git-tag in order for workload create/update/apply to succeed, found out user has to provide either --git-tag, --git-branch or both if they want want to provide --git-commit in order to create the workload from a specific commit.
Yet, this issue is blocked by the usage of the current version of FluxCD Source Controller (0.16) in Tanzu Application Platform

Proposed solution

1. Update the version of FluxCD
2. Remove client-side validation for mutual inclusion of (--git-branch or --git-tag) when --git-commit is provided

Additional context

• https://github.com/vmware-tanzu/tanzu-cli-apps-plugins/commit/ef67dc59ae3fc853fa0719002a0e3012c302c3f7
• Source controller fails to clone when specifying just the revision (and default branch main at origin) fluxcd/source-controller#315
• git: refactor authentication, checkout and verification fluxcd/source-controller#462

Issue originally submitted by @warango4