chore: remove start event handler

[yanksyoon]

Applicable spec: N/A

Overview

Remove start event handler.

Rationale

It doesn't quite do anything.

Juju Events Changes

N/A

Module Changes

N/A

Library Changes

N/A

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing 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)

[arturo-seijas]

LGTM

[yanksyoon]

This is on hold until the defers / start event deletion is safe to do.

[github-actions]

Test coverage for 4301278

Name                Stmts   Miss Branch BrPart  Cover   Missing
---------------------------------------------------------------
src/charm.py          517     37    168     29    90%   188-191, 542, 573, 619, 654-655, 706-713, 718, 820->825, 824, 826, 831-832, 892, 910, 917, 1009, 1018, 1030, 1051, 1060, 1079, 1083, 1112, 1165, 1297, 1319, 1326->1328, 1371->exit, 1383, 1415, 1424-1425
src/cos.py             15      0      0      0   100%
src/exceptions.py      17      1      2      1    89%   41
src/types_.py          15      0      0      0   100%
---------------------------------------------------------------
TOTAL                 564     38    170     30    90%

Static code analysis report

Run started:2023-10-24 10:08:54.585936

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 4243
  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):