Chore: remove redundant rustfmt.toml from decimal-byte-parts, fsst, alp

These per-crate rustfmt.toml files only contained imports_granularity = "Module"
which is now handled by the root rustfmt.toml configuration.

Signed-off-by: Joe Isaacs <[email protected]>

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: joseph-isaacs