Summary:
Fix violations of postgres lint rule bad_spacing_after_comment, then
turn it from a warning to an error.

Jira: DB-17293

Test Plan:
On Almalinux 8:

    { arc lint src/postgres/**/*.c; arc lint src/postgres/**/*.h; } \
      | grep bad_spacing_after_comment

should return no results.

Close: #27693

Reviewers: patnaik.balivada

Reviewed By: patnaik.balivada

Subscribers: yql

Differential Revision: https://phorge.dev.yugabyte.com/D44810