Backport !1976 “Use the right permissions for directory watching on Win32” to glib-2-66
Using FILE_GENERIC_READ | FILE_GENERIC_WRITE access rights for directory monitoring might cause problems, as noted in gimp#4594 (closed).
ReadDirectoryChanges only needs FILE_LIST_DIRECTORY, so use that.
Fixes: gimp#4594 (closed)
Trivial backport of !1976 (merged) to glib-2-66
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