chore(member merge) increase max length of user email on organizationmember model

[mifu67]

Apologies, I think this should be the last change necessary to support sentry app proxy user placeholder emails.

[github-actions]

This PR has a migration; here is the generated SQL for src/sentry/migrations/0913_increase_orgmember_user_email_max_length.py

for 0913_increase_orgmember_user_email_max_length in sentry

--
-- Alter field user_email on organizationmember
--
ALTER TABLE "sentry_organizationmember" ALTER COLUMN "user_email" TYPE varchar(200);

[codecov]

⚠️ Parser warning

The parser emitted a warning. Please review your JUnit XML file:

Warning while parsing testcase attributes: Limit of string is 1000 chars, for name, we got 2083 at 1:156718 in /home/runner/work/sentry/sentry/.artifacts/pytest.junit.xml