Fix for validate release links script

[ervteng]

Proposed change(s)

Fixes two minor issues with the validate_release_links script.

• Don't try to replace when there is no pip install line
• Match Python versions with more than one digit per number (e.g. X.YY.Z).

Types of change(s)

• Bug fix
• New feature
• Code refactor
• Breaking change
• Documentation update
• Other (please describe)

Checklist

• Added tests that prove my fix is effective or that my feature works
• Updated the changelog (if applicable)
• Updated the documentation (if applicable)
• Updated the migration guide (if applicable)

Other comments

[chriselion]

Sorry about that!