Fix broken contact reference in contributing.rst by adding proper contact link

[asgardik0]

What

Fixed two instances of broken :ref:Talk `` references in CONTRIBUTING.rst

Changes Made

• Replaced :ref:Talk to developers with proper RST link Talk to developers <https://docs.pytest.org/en/stable/contact.html>_ in the "Fix bugs" section
• Replaced :ref:Talk to developers with proper RST link Talk to developers <https://docs.pytest.org/en/stable/contact.html>_ in the "Implement features" section

Why

The original reStructuredText :ref: syntax was malformed and not rendering as clickable links, which could confuse new contributors trying to contact the development team. The new links directly point to the pytest contact documentation page.

Result

Now contributors can easily click through to the contact channels page instead of seeing broken references.

[bluetech]

The links are not broken, as can be seen here: https://docs.pytest.org/en/stable/contributing.html#fix-bugs. Can you explain where you saw this?

[asgardik0]

The links are not broken, as can be seen here: https://docs.pytest.org/en/stable/contributing.html#fix-bugs. Can you explain where you saw this?

The link are broken here: https://github.com/pytest-dev/pytest?tab=contributing-ov-file#fix-bugs and here: https://github.com/pytest-dev/pytest?tab=contributing-ov-file#implement-features
where :ref:Talk <contact> doesn't work.
On my commit I changed the link to this: https://docs.pytest.org/en/stable/contact.html

[bluetech]

The links are meant for the Sphinx-build docs but I guess CONTRIBUTING.rst specifically is more likely to be read through github which doesn't resolve such references. So I figure we can make an exception for it and merge this. Thanks.