.gitattributes

tests: fix hooks in `test-transaction-rollback-on-revlog-split.t` for Windows

A few problems with external hooks here:

  1) `cmd.exe` is blissfully unaware of the meaning of single quotes, and passes
     them along as part of the revision arg
  2) `cmd.exe` doesn't know how to run the python script `f` with the shebang
     line, so it needs to be invoked with the intepreter explicitly.  Then for
     some reason it was trying to open `$TESTTMP\troffset-computation-hooks\f`,
     so make it an absolute path.
  3) Likewise, the shell script `wait-on-file` cannot be invoked directly by
     `cmd.exe`.
  4) Windows python doesn't understand whatever `$TESTTMP` unrolls to (probably
     it has the double backslashes), and silently failed to write the lock file.

I'm assuming that `pretxnclose.03-abort` is also bad (there's no `false` in
`cmd.exe`), but it's not currently causing problems.

Also note that the paths in this are very long, and typically exceed the
`MAX_PATH` limit in Windows.  It can be run with `run-tests.py --tmpdir /c/t`.

# So GitLab doesn't think we're using tons of Perl
*.t -linguist-detectable