Update to Rust 1.71.1

[mathias-arm]

• Newer versions of some dependencies have started to require Rust 1.71.
• CI runs faster with Rust 1.71 compared to 1.67 because Cargo uses the new crates sparse index.
• The update allows for some de-duplications in Cargo.lock.
• Warning mentioned in Compiler warning for quick-xml #236 is now visible with Rust 1.71.