worker: silence type error when calling pickle pytype is complaining that the argument to `pickle.load()` is not an `IO`. pytype isn't wrong: `_blockingreader` doesn't implement `io.RawIOBase`, only `read()` and `readline()`. But it appears this is enough for pickle. So we silence the false positive. This fixes a regression introduced by D12304 / cc0e059d2af8: worker: remove Python 2 support code. Differential Revision: https://phab.mercurial-scm.org/D12337

stringutil: remove Python 2 support code Differential Revision: https://phab.mercurial-scm.org/D12314

procutil: delete Python 2 support code This entailed deleting a function for Python 2 support and renaming the Python 3 function to match the exported symbol name. Differential Revision: https://phab.mercurial-scm.org/D12313

revlogutils: unconditionally pass version to random seed Differential Revision: https://phab.mercurial-scm.org/D12312

revlogutils: remove Python 2 variant for iter_seed Differential Revision: https://phab.mercurial-scm.org/D12311

charencode: remove Python 2 support code Differential Revision: https://phab.mercurial-scm.org/D12310

hgweb: remove Python 2 support code Differential Revision: https://phab.mercurial-scm.org/D12309

hgweb: remove Python 3 conditional We probably have a better tobytes() implementation somewhere in pycompat. But I don't want to bloat scope of this commit. Differential Revision: https://phab.mercurial-scm.org/D12308

hgweb: simplify uenv assignment We don't need the Python 3 conditional. We can call items() directly since we're on Python 3 now. Differential Revision: https://phab.mercurial-scm.org/D12307

chgserver: remove Python 2 support code The logic here is more complicated than most Python 2/3 support code. But the rewritten logic should be identical. Differential Revision: https://phab.mercurial-scm.org/D12306