Bump linuxbrew/Homebrew from `9308a25` to `b15c6b1`
Bump linuxbrew/Homebrew from `9308a25` to `b15c6b1`

Bumps [linuxbrew/Homebrew](https://github.com/Homebrew/brew) from `9308a25` to `b15c6b1`.
- [Release notes](https://github.com/Homebrew/brew/releases)
- [Commits](https://github.com/Homebrew/brew/compare/9308a2515bff26fc090501fbbcd72acdb4ffa8be...b15c6b1fcee23c3f4b66f5901ab70635ed3fdc2b)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
doot/dotfiles,doot/dotfiles