feat(chart): 📝 version support with annotations

[darkweaver87]

What does this PR do?

Declares supported Traefik Proxy and Hub version ranges as Chart.yaml annotations
(traefik.io/proxy-min-version, proxy-max-version, hub-min-version, hub-max-version),
replacing hardcoded values in templates.

Motivation

Fixes #1758

More

• Yes, I updated the tests accordingly
• Yes, I updated the schema accordingly
• Yes, I ran make test and all the tests passed

[mloiseleur]

First review.

1. Changelog is not updated as expected.
2. Tests on notes.txt will probably annoy us. Wdyt of reducing and/or simplifying them ?

[darkweaver87]

Thanks for the revie @mloiseleur. Here my changes to address your comments:

• test-changelog.yaml: populate VERSION_SUPPORT so the fixture gets the ## 👌 Traefik version support section.
• changelog.json: bump max_pull_requests 300 → 500 (the tag window holds 352 PRs, docs: 📚️ fix typo in Guidelines.md #1320 was being cut off — example failing run).
• hack/test.sh: copy chart to /tmp and pin version-support annotations there, decoupling tests from the real ranges. Same pin in test-changelog.
• Drop 3 redundant "no-warning when in range" NOTES tests.
• Rebased onto v40.0; Chart.yaml annotations adjusted (proxy-max v3.7.0-rc.1, hub-min v3.19.3, hub-max v3.20.0-rc.1).

[mloiseleur]

changelog.json: bump max_pull_requests 300 → 500 (the tag window holds 352 PRs,

That seems very high. We have between 2 and 20 PRs for a single release.
And it looks like we would have to increase it even more in a year or two.
🤔 Wdyt about adding a date filter ? Do we have any other better option, like starting from the previous tag ?

[darkweaver87]

changelog.json: bump max_pull_requests 300 → 500 (the tag window holds 352 PRs,

That seems very high. We have between 2 and 20 PRs for a single release. And it looks like we would have to increase it even more in a year or two. 🤔 Wdyt about adding a date filter ? Do we have any other better option, like starting from the previous tag ?

fetchViaCommits: true seems to fix our issue :-)

[mloiseleur]

Seems a bit excessive to copy everything when we need here to set specific value for consistent test.
Wdyt about:

1. Open an issue on https://github.com/helm-unittest/helm-unittest about the capacity to set this kind of field
2. Explore if we can use postRenderer to avoid this
3. Use helm plugin install of docker, so it could at least be done in place, by saving current values and restoring them afterwards (example here)

[darkweaver87]

1. yes this is the long-term response to this problem
2. postRenderer transforms the output but not the evaluation of templates (cf. https://github.com/helm-unittest/helm-unittest/blob/main/pkg/unittest/test_job.go#L491; TLDR if statements are evaluated at rendering time)
3. done in 0fcd9c8