feat(admission) add secret filter

[rainest]

What this PR does / why we need it:

Chart manifest component of Kong/kubernetes-ingress-controller#5856

Removes the secrets entry from the existing webhook.

Adds an ingressController.admissionWebhook.filterSecrets boolean value. When true, it creates webhooks that accept only Secrets with known KIC-relevant labels. When false, it creates a webhook that accepts any (non-Helm) Secret.

Special notes for your reviewer:

Checklist

[Place an '[x]' (no spaces) in all applicable fields. Please remove unrelated fields.]

• PR is based off the current tip of the main branch.
• Changes are documented under the "Unreleased" header in CHANGELOG.md
• New or modified sections of values.yaml are documented in the README.md
• Commits follow the Kong commit message guidelines

[czeslavo]

I've regenerated golden files using the latest version of chartsnap to reduce changes volume: eceadb9

Chartsnap in v0.3.0 changed the format of golden files from TOML to YAML and I adopted this format in #1054. One mistake I made was to not enforce a local version to always match the one defined as desired. This should fix it for the future: #1064.