Bump riscv-gnu-toolchain from `51c7370` to `65056bd`

Bumps [riscv-gnu-toolchain](https://github.com/riscv/riscv-gnu-toolchain) from `51c7370` to `65056bd`.
- [Release notes](https://github.com/riscv/riscv-gnu-toolchain/releases)
- [Commits](https://github.com/riscv/riscv-gnu-toolchain/compare/51c73700789f54db7e8c22e5bf1654bcfdd074d0...65056bdb149c87db4e7223c4e8b5466cf326ff86

)

---
updated-dependencies:
- dependency-name: riscv-gnu-toolchain
  dependency-type: direct:production
...

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