Update Rust crate glib to ^0.19.3

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
glib (source)	dependencies	patch	^0.19.2 -> ^0.19.3

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Release Notes

gtk-rs/gtk-rs-core (glib)

v0.19.3

Compare Source

Matthew Waters:
      pango: add some missing AttrInt constructors.

Paolo Borelli:
      macros: allow to specify #[default] for glib::flags

Sebastian Dröge:
      glib: Add `Quark::from_static_str()`
      glib: Use `Self` instead of `Quark` in a few places
      glib: Drop the main context future return value sender on finalize
      glib: Fix memory leak in `subclass::shared` tests
      glib: Use `glib::GString` for collate keys
      glib: Avoid heap allocation and copy of input strings for collation
      glib: Don't misuse `slice::get_unchecked()`
      Update versions to 0.19.3

Ville Hakulinen:
      gio: correctly free argument list items
      tests: skip failing test on windows

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