clonebundles: stop shell quoting `HGCB_BUNDLE_BASENAME` environment variable
This causes problems in `test-clonebundles-autogen.t` on Windows, because the
quoted path ends up being passed to the `cp` command, which fails, because quote
characters are not a legal part of a file name. I don't see any quoting in
environment variables on either MSYS or WSL, even with weird ones that appear to
have escape sequences like `PS1=\[\033]0;$MSYSTEM:\w\007` (in MSYS). The
quoting was added back in 5ae30ff79c76, and as shown here, was causing problems
even on posix when a quote was slipped into the path.
(The other obvious problem is that the command is spun up shell style, which
invokes `cmd.exe`, which doesn't know about `$foo` style variables. That will
be addressed next, but that change didn't work without this too.)
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}