setup: use the full executable manifest from `python.exe` The manifest embedded by the build process (before the string here is added) already accounts for the `<requestedExecutionLevel level="asInvoker" ...>` setting. (Note that the PyOxidizer build is missing this, so it will likely trigger the UAC escalation prompt on each run.) However, using `mt.exe` to merge the fragment with what is already in the manifest seems to strip all whitespace, making it unreadable. Since Mercurial can be run via `python.exe`, it makes sense that we would have the same manifest settings (like the supported OS list), though I'm unaware of any functionality this enables. It also has the nice effect of making the content readable from a resource editor. The manifest comes from python 3.9.12. Note that this seems to strip the `<?xml ... ?>` declaration when viewed with ResourceHacker 5.1.7, but this was also the state of things with the previous commit, and `mt.exe "-inputresource:hg.exe;#1" -out:extracted` does contain the declaration and the BOM in both cases. No idea why this differs from other executables.