Update Python.gitignore to include .env.example

[Axwaizee]

Add exception for .env.example in gitignore

Link to the application or project's homepage

https://github.com/github/gitignore

Reasons for making this change

The Python.gitignore template ignores .env files (since they typically hold secrets like API keys and database credentials). However, this same rule also matches .env.example, a template file that intentionally contains no secrets and is meant to be committed to the repo so other contributors know which environment variables to set up. Right now, anyone who creates a .env.example file has it silently ignored and has to manually force-add it or edit their .gitignore. Adding a negation rule (!.env.example) keeps .env ignored while explicitly un-ignoring the safe example file, matching common convention (e.g. .env.example, .env.sample) used across many Python projects.

Links to documentation supporting these rule changes

• https://github.com/github/gitignore/blob/main/Python.gitignore (current .env rule)
• General convention discussed here: https://salferrarello.com/add-env-to-gitignore/
• Related community request for broader .env* handling: Add wildcard so that all .env files are ignored - Python.gitignore #4393

Merge and Approval Steps

• I have read the contribution guidelines and understand my PR will be closed if it doesn't meet these guidelines