Minor help glitch in `cabal-validate`

**Describe the bug**
`--no-solver-benchmarks` has the same help text as `--solver-benchmarks`.
```
--solver-benchmarks Build and trial run `solver-benchmarks`
--no-solver-benchmarks Build and trial run `solver-benchmarks`
```

**To Reproduce**
`./validate.sh --help`

**Expected behavior**
I would expect `--no-solver-benchmarks to say it does _not_ build and run the solver benchmarks.

**System information**
- Linux x86 (Ubuntu 24.04)
- cabal HEAD, ghc 9.6.6

Start with validate.sh and the cabal-validate --help entry point, then locate the definitions for --solver-benchmarks and --no-solver-benchmarks. Update the latter's help text to describe that it does not build or run solver benchmarks, and run ./validate.sh --help to verify the output.

Written by the indexing model from the issue text.