Support stable Rust toolchain

[dcoles]

Currently Rust for Flipper Zero requires a nightly toolchain to build binaries. This makes development somewhat more difficult as we have to regularly update this to pull in new features or bug fixes.

Blockers to supporting a stable Rust toolchain

• [x] rust-lang/rust#66741: Stable as of Rust 1.68.0
• [x] rust-lang/rust#90275: Flipper Zero's dynamic linker does not support unique section names
• [ ] rust-lang/rust#44839: arm_target_features is used to match our specific ARM target
• [ ] rust-lang/cargo#9778: different_binary_name feature is needed to set .fap file extension

[dcoles]

A possible alternative to waiting for no-unique-section-names is to teach the Flipper Zero linker about non-unique section names.

[dcoles]

It appears that the Flipper Zero linker can now handle non-unique section names making -Z no-unique-section-names unneeded.