The Windows runner's TEMP is on C:, where a flush took about 6 ms and a test
database's create-to-delete about 111 ms; on D: the same took 0.5 ms and
23 ms. The job now points TEMP/TMP at RUNNER_TEMP and lists the 40 slowest
tests. The fake HTTPS handlers get a TLS context that reads no certificate
store, and the missing-share tests name localhost instead of an unknown
server. The temporary diagnostics are removed.