typing: simplify archive.gz writing and drop a few pytype suppressions I was waiting until 3.8 to use `Literal` to fix this, but there's also the ":" and "|" characters that are passed along here, meant only for the non-gz archive types. But manipulating what the local caller passes is silly- we know we're writing, so just open it for writing. As an added bonus, PyCharm stops flagging the call too (since it doesn't know about pytype suppression comments).

typing: explicitly set the return type of `_InnerRevLog.raw_text()` Somewhere between cd72a88c5599 and 2fd44b3dcc33, pytype changed the return type from `Tuple[_T1, Any, bool]` to `Any`. Both are wrong. `mdiff.patches()` is an alias for `mpatch.patches()`, which is selected via module policy (and breaks the ability to infer the types). However, `cext`, `cffi`, and `pure` implementations all agree it returns bytes.