Fix yq -i reformatting that breaks helm chart lint

The product-release.yml workflow in rstudio/helm uses yq -i to
update values.yaml in place, which re-serializes the whole file and
drops formatting that ct lint requires. This broke the auto-generated
release PR's lint check.

rstudio/helm PR #917 (dispatched from this repo's images-connect
production release) failed with:

479:27 [comments] too few spaces before comment
480:28 [comments] too few spaces before comment
482:29 [comments] too few spaces before comment

The diff shows why: yq's re-serialization collapsed inline comment
padding from 2 spaces to 1 (e.g. ServiceLogLevel: INFO # ... became
ServiceLogLevel: INFO # ...) and stripped ~75 blank lines that
separated top-level and nested keys throughout the file. ct lint's
embedded yamllint config requires min-spaces-from-content: 2, so any
comment yq collapses to 1 space fails the job.

The "Sync Connect interpreter paths" step is the culprit — it's the
only step that rewrites values.yaml as a whole document (the
Chart.yaml bump step only touches Chart.yaml):

yq -i ".config.Python.Executable = [...]" "charts/${CHART_NAME}/values.yaml"

Possible directions:

• Replace the yq -i on values.yaml with a targeted substitution
  (e.g. sed) that touches only the one field, avoiding a
  full-document re-serialization.

• Add a normalization step after any yq -i call that restores
  minimum-2-space comment padding before the PR is opened.

• https://github.com/rstudio/helm/pull/917

Start with the “Sync Connect interpreter paths” step in product-release.yml and inspect how it rewrites charts/${CHART_NAME}/values.yaml. Run the chart lint workflow or ct lint against the generated values.yaml, then verify that the release PR passes without collapsing comment spacing or removing blank-line formatting.