fix: add :enabled sub-config for fixer tools This allows distributing opt-in fixer tool configurations in .hgrc files. This may be useful for adding default configs in core, or for orgranizations that want to provide configs to their users. Tools are still enabled by default because it would be confusing to add a config and find that it has no effect until you add enabled=true. Differential Revision: https://phab.mercurial-scm.org/D6975

automation: add a command to submit to a Try server The CI code for running the Try Server requires more thorough review. Let's add just the client-side bits for submitting to Try so others can start using it. Differential Revision: https://phab.mercurial-scm.org/D6983

automation: improve documentation for credentials management Differential Revision: https://phab.mercurial-scm.org/D6982

automation: switch to us-west-2 by default This is where the AWS account I'm running lives. Differential Revision: https://phab.mercurial-scm.org/D6981

automation: upgrade various packages Ran `pip-compile -U` to upgrade to latest versions. Differential Revision: https://phab.mercurial-scm.org/D6980

statprof: drop python #! and exec bit we don't use For some reason this wasn't flagged until I ran a reformatter on this file. I'm deeply confused by this, but since we don't execute this drop the support for it. Differential Revision: https://phab.mercurial-scm.org/D6985

cvsps: switch a file open to a with statement For some reason this only showed up in check-code after running black. Puzzling. Differential Revision: https://phab.mercurial-scm.org/D6984