tests: use %b64[] instead of "raw" base64

[bagder]

No description provided.

[Copilot]

Pull request overview

Updates existing mail-auth test fixtures to generate SASL PLAIN base64 payloads via the test preprocessor instead of embedding raw base64 blobs, improving readability and maintainability of the test data.

Changes:

• Replace hardcoded base64 auth strings with %b64[... ]b64% tokens in SMTP/POP3/IMAP related tests.
• Represent NUL-separated SASL PLAIN fields using %00 hex escapes inside the %b64[...] payload.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/data/test954	Switch SMTP AUTH PLAIN base64 payloads (servercmd + protocol verify) to %b64[...]b64%.
tests/data/test953	Switch SMTP AUTH PLAIN base64 payloads (servercmd + protocol verify) to %b64[...]b64%.
tests/data/test893	Switch POP3 AUTH PLAIN base64 payloads (servercmd + protocol verify) to %b64[...]b64%.
tests/data/test849	Switch IMAP AUTHENTICATE PLAIN base64 payloads (servercmd + protocol verify) to %b64[...]b64%.
tests/data/test795	Switch IMAP AUTHENTICATE PLAIN initial response from raw base64 to %b64[...]b64%.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[testclutch]

Analysis of PR #21313 at b585aa1c:

Test ../../tests/http/test_05_errors.py::TestErrors::test_05_09_handshake_eof failed, but it has been 9.5% flaky lately, so it's probably NOT a fault of the PR. Note that this test has failed in 2 different CI jobs (the link just goes to one of them).

Test 1675 failed, which has NOT been flaky recently, so there could be a real issue in this PR. Note that this test has failed in 2 different CI jobs (the link just goes to one of them).

Generated by Testclutch