Log Message:
librsvg: update to 2.56.3.

Version 2.56.3
==============

This is a security release for bug #996.

- #996 - Fix arbitrary file read when href has special characters.

- #998 - Fix cascade for symbol elements being referenced from use elements.

Version 2.56.2
==============

- Windows build fixes (Chun-wei Fan).

Version 2.56.1
==============

- The minimum supported Rust version (MSRV) is 1.65.  Unfortunately
  the assert_cmd crate, used in the test suite, bumped its MSRV and is
  forcing us to do the same.

- #965 - Shrink the shared library by telling the linker to omit
  unused code (Sebastian Dröge).

- Updates to dependencies (Lukáš Tyrychtr, Kalev Lember).