Re-enable pii_check linting

[kdmccormick]

The pii_check in edx-platform not running for a long time. We want to re-enable it as part of:

• Replace Paver quality and js_test commands [Paver Removal 2/3] #35159

However, running code_annotations with the --lint flag currently raises errors due to some malformed PII annotations. In particular, these annotations from edx-proctoring need to be fixed:

• Fill in pii_retirement: to_be_implemented edx-proctoring#1241

So, in the PR linked above, we have removed the --lint flag from make pii_check. This issue exists as a reminder for us to put the --lint flag back once the edx-proctoring issue, and any other pii linting errors, are resolved.

Please note that this is separate from @bmtcril 's effort to raise the PII annotation threshold, which is checked by nature of us passing the flag --coverage to code_annotations:

• chore: Add missing PII annotations, update safelist #35779