Evaluate whether bug list of `std.functional.toDelegate` is up-to-date

[0xEAB]

The documentation of std.functional.toDelegate currently lists two bugs.

phobos/std/functional.d

Lines 1809 to 1813 in fcffbc0

	* BUGS:
	* $(UL
	* $(LI Does not work with `@safe` functions.)
	* $(LI Ignores C-style / D-style variadic arguments.)
	* )

I think that now that #10599 has been merged, toDelegate should work fine with @safe functions.
If so, the corresponding bug entry should be removed.

[gulugulubing]

I'm a new contributor and would like to help with this issue.I verified toDelegate now supports @safe functions and update the documentation.
Please let me know if there's anything I should pay attention to.