Bump toolchains/riscv-tools/riscv-tests from e2cdf46 to 51de008

Bumps [toolchains/riscv-tools/riscv-tests](https://github.com/riscv-software-src/riscv-tests) from `e2cdf46` to `51de008`.
- [Commits](riscv-software-src/riscv-tests@e2cdf46...51de008)

---
updated-dependencies:
- dependency-name: toolchains/riscv-tools/riscv-tests
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>