BUG: pre-commit script to find .env has bad regex

[tomwillis608]

In the script to prevent the submission of .env files, there is a regex bug, per ChatGPT

Actual:
the script

#!/bin/sh
if git diff --cached --name-only | grep -q "^.env$"; then
    echo "Error: Attempt to commit forbidden file '.env'"
    exit 1
fi

Fix:

We escape each literal dot with \. so \.env only matches files that start with a dot.