Create sets of values files that pass install tests with the chart testing tool

[jforest]

EDIT: David Kegley added a step to run helm unittesting in the GHA. We will use these install tests and also use those unittests

Looking at this comment from David Kegley:

That makes sense, seems like we have the install half but are missing the assertions. I believe we just need to write some tests that live in the charts/rstudio-connect/templates/test directory and it sounds like they will get evaluated automatically by each ct install

https://helm.sh/docs/topics/chart_tests/
https://github.com/helm/chart-testing/blob/main/doc/ct_install.md#synopsis

I will explore if we can get some assertions set. EDIT: David already submitted and merged a PR to run helm unittest on the charts

The test suite does run by default: https://github.com/rstudio/helm/actions/runs/11560585710/job/32177753331#step:13:606 is an example. We only have that one single test in all the helm charts so far EDIT: Removed that one test as unneeded since the install tests do the same thing