typing: add some type hints to fastannotate that have decayed in the last year Somewhere since 10db46e128d4, `_knownopts` decayed to `set` for unknown reasons. Also, `annotateopts.default` changed from bytes to str. While that is correct, I noticed that PyCharm was flagging the member fields as undefined in `shortstr()`, so add those to keep it happy. (There are no complaints from pytype because that module is excluded, due to the missing reference to `linelog.copyfrom()` that I'm not sure how to fix.)

heptapod-ci: use new v2.1 image This is finally catching up to ~3 years of tech debt.

heptapod-ci: move version prints closer to the start This makes debugging a lot easier if anything is to go wrong, and shows output earlier.

pytype: only try the hacky way of finding PYTHON if not provided This allows us to work in more environments, like when using pyenv. This syntax is compatible with all POSIX shells.

dummysmtpd: fix EOF handling on newer versions of OpenSSL Explanations inline.

test-install: add new glob for the upgrade notice in newer versions of pip We only globbed for the old warning, newer versions of pip use a cleaner one.

rust: use `.cargo/config.toml` instead of `.cargo/config` This has been deprecated for a while now and we don't support Rust versions that only understand the old path.