Correct "can not" to "cannot" in messages, comments, etc.

[Eilon]

Both are correct, but "cannot" is preferred and far more common: https://www.merriam-webster.com/grammar/cannot-vs-can-not-is-there-a-difference

In some cases it is a user-facing message, such as certain XAML errors:

maui/src/Controls/src/Xaml/MarkupExtensions/ReferenceExtension.cs

Line 36 in 4856f37

throw new XamlParseException($"Can not find the object referenced by `{Name}`", serviceProvider);

And if you run into this type of error, you see it in Visual Studio. And it looks weird.

@spadapet , @jfversluis , @jonathanpeppers , @Redth - tagging all of you because you were participating in my discussion of this in a recent meeting. Very easy PR to review!

Notes:

• I'm submitting to net9 because this is ultimately minor.
• I left a few instances of can not in the repo because they are quoting other things like bug titles, so I left them as-is.

[jonathanpeppers]

I cannot disapprove.

[jfversluis]

[jfversluis]

OK I think after 6 attempts maybe something is actually wrong with the still failing test...