Retag flyteagent image upon release

[eapolinario]

Tracking issue

NA

Why are the changes needed?

In https://github.com/flyteorg/flyte/pull/5360 we made a decision to join flytekit and Flyte releases, but that turned out to be too inflexible.

What changes were proposed in this pull request?

In this PR we decouple the versions of the flyteagent from the Flyte release versions. Instead, we follow a similar scheme as the one we use for flyteconsole and upon releases we retag the latest flyteagent docker image.

On releases we retag the images by adding the suffix -release to each component image. We're going to do the same with flyteagent images, which are published on flytekit releases.

How was this patch tested?

Running VERSION=1.99.0 make release_automation from the root of the repo updated all helm charts, including the flyteagent image (to 1.12.3, which is the latest flytekit image at the time of this PR).

Setup process

Screenshots

Check all the applicable boxes

• [ ] I updated the documentation accordingly.
• [ ] All new and existing tests passed.
• [ ] All commits are signed-off.

Related PRs

Docs link

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 60.99%. Comparing base (3ee7120) to head (9bc7e10).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #5509 +/- ## ======================================= Coverage 60.98% 60.99% ======================================= Files 794 794 Lines 51475 51475 ======================================= + Hits 31392 31397 +5 + Misses 17191 17186 -5 Partials 2892 2892 ``` | [Flag](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | Coverage Δ | | |---|---|---| | [unittests-datacatalog](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `69.31% <ø> (ø)` | | | [unittests-flyteadmin](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `58.73% <ø> (+0.04%)` | :arrow_up: | | [unittests-flytecopilot](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `17.79% <ø> (ø)` | | | [unittests-flytectl](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `68.03% <ø> (ø)` | | | [unittests-flyteidl](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `79.04% <ø> (ø)` | | | [unittests-flyteplugins](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `61.85% <ø> (ø)` | | | [unittests-flytepropeller](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `57.30% <ø> (ø)` | | | [unittests-flytestdlib](https://app.codecov.io/gh/flyteorg/flyte/pull/5509/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg) | `65.57% <ø> (-0.03%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=flyteorg#carryforward-flags-in-the-pull-request-comment) to find out more.

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