Fix syntax for checking if pre-commit is installed in isaaclab.sh

[louislelay]

Description

When running ./isaaclab.sh --format for another pull request, I got a command not found error for pre-commit. Looking into the script, I found a condition to check if pre-commit was installed, but the syntax was off.

It was written like this:

if [ ! command -v pre-commit &>/dev/null ]; then

But it should be:

if ! command -v pre-commit &>/dev/null; then

I fixed it, and the script worked as expected, installing pre-commit when I ran it again.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there