fix: schema for agent.image.pullSecrets

[tredmon]

Description

The agent.image.pullSecrets is referenced by the deployment.yaml but is currently disallowed by the schema file. I need to use this configuration setting in my k8s environment. I currently use a workaround of helm upgrade --skip-schema-validation but it would be nice not to need to skip validation.

Checklist

• I made sure to update ./CHANGELOG.yml (our release notes are generated from this file).
• I made sure to add any documentation changes required for my change.
• My change is adequately tested.
• I updated CONTRIBUTING.md with any special dev tricks I had to use to work on this code efficiently.
• Once my PR is ready to have integration tests ran, I posted the PR in #telepresence-oss channel on the
  CNCF Slack so that the "ok to test" label can be applied.

[thallgren]

This looks good to me, but please ensure two things:

1. Run make docs-files so that your addition gets included in the docs.
2. You must sign off on your commit.

[tredmon]

make docs-files only modified the default config path to it's location on MacOS in 86 different files in the docs folder. That didn't seem like a worthwhile change to commit.

-      --config string     Path to the Telepresence configuration file (default "$HOME/.config/telepresence/config.yml")
+      --config string     Path to the Telepresence configuration file (default "$HOME/Library/Application Support/telepresence/config.yml")

I've now signed off on the commit, and manually added missing documentation to the chart's README.md.

Oh, looks like make docs-files only runs against the most recent commit (either that or I just missed it among all the default config path changes). Since I had a commit for my change followed by a merge commit it didn't originally run against my change. Now that I've rebased everything on release/v2 and my commit was the latest, running make docs-files did produce some useful changes. I've added those to my commit as well now.

[thallgren]

The build is currently failing due to an external problem: https://gitlab.alpinelinux.org/alpine/aports/-/issues/17775. I expect it go get fixed very soon. I'll rerun the build and merge once that happens.