Bump Rust to version 1.73.0

Bump Rust to version 1.73.0

- Update rust compiler from 1.65.0 to 1.73.0
  because some third party dependencies for
  GLFM Markdown require a newer version.

Related https://gitlab.com/gitlab-org/ruby/gems/gitlab-glfm-markdown/-/issues/2

Signed-off-by: Brett Walker <bwalker@gitlab.com>

What does this MR do?

https://gitlab.com/gitlab-org/ruby/gems/gitlab-glfm-markdown needs at least 1.70.0 - update to latest 1.73.0

Related issues

Related: gitlab-org/ruby/gems/gitlab-glfm-markdown#2 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated
• New dependencies are managed with dependencies.io