Ignore `tests` when running toggles/settings reports

[sarina]

the problem

When running toggles/settings reports (make requirements, cd docs/, make xml), we get some garbage like

+MYTOGGLE
\ \ \ \ #\ ..\ toggle_default:\ something:
`.venv/lib/python3.11/site-packages/test/plugins/test_annotations_check.py (line 203)
<https://github.com/openedx/edx-platform/blob/cf48323639bf24eed5ef120dfbd9e98cf0fd64af/
    .venv/lib/python3.11/site-packages/test/plugins/test_annotations_check.py#L203>

which means the annotations report is finding this line: https://github.com/openedx/edx-lint/blob/dcb92c5fbe81da24ec7a4a1029b0809b4fbbfccf/test/plugins/test_annotations_check.py#L148

And it's seeing that line because it's within the .venv within the edx-platform checkout.

T he issue is the confluence of three things:

• edx-lint is installed during the docs build
• edx-lint's test files are included in the docs build
• edx-lint contains strings that look like annotations, but they're actually just for testing the annotation system themselves

The fix

Get this source file out of the build somehow.

• this could mean uninstalling edx-lint (perhaps by pip-installing requirements from base.txt instead of dev.txt?).
• this could also mean skipping directories named tests and files named test_*.py when buildings docs <- this is where I'd start

[sarina]

Ref: openedx/wg-build-test-release#553 (comment)