Re-check Vale and fix errors

[erinecon]

Applicable ticket: ISD-3949

Overview

Run Vale checks locally and fix errors.

Rationale

There's a bug in operator-workflows that points to an older version of the Canonical Vale style checks. Therefore some of the checks will be missed in the GitHub CI.

Juju Events Changes

None

Module Changes

None

Library Changes

None

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Manging Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

There are no src docs.
Either discourse-gatekeeper will update the documentation on Charmhub or I'll do it after the approval of this PR.

[github-actions]

Test results for commit aa51053

Test coverage for aa51053

Name           Stmts   Miss Branch BrPart  Cover   Missing
----------------------------------------------------------
src/charm.py       7      1      2      1    78%   20
----------------------------------------------------------
TOTAL              7      1      2      1    78%

Static code analysis report

Run started:2025-08-06 20:15:12.468012

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 671
  Total lines skipped (#nosec): 1
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):