Disable external HTTP request in wp theme list and wp plugin list command

[weiiwang01]

The wp-cli commands wp theme list and wp plugin list by default connect to the WordPress website to check for theme and plugin updates. However, this is unnecessary for the charm's use case and can slow down the command, especially in environments without internet connectivity.

Add --exec=define('WP_HTTP_BLOCK_EXTERNAL', TRUE); to disable all external HTTP requests during these two commands. And to my surprise, --skip-update-check does not work.

[github-actions]

Test coverage for bfe6e7a

Name                Stmts   Miss Branch BrPart  Cover   Missing
---------------------------------------------------------------
src/charm.py          540     35    182     32    91%   186-189, 353-354, 413->417, 566, 597, 603, 620-624, 654, 689-690, 747, 756, 860->873, 872, 874, 879-880, 940, 958, 965, 1055, 1064, 1076, 1097, 1106, 1125, 1129, 1158, 1211, 1343, 1365, 1372->1374, 1417->exit, 1429, 1445, 1482
src/cos.py             15      0      0      0   100%
src/exceptions.py      17      1      2      1    89%   41
src/state.py           34      0      4      0   100%
src/types_.py          16      0      0      0   100%
---------------------------------------------------------------
TOTAL                 622     36    188     33    91%

Static code analysis report

Run started:2024-02-27 16:21:19.782562

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 4430
  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):