Reduce automated builds in GitHub Actions

[kmcginnes]

Description

There is no need to run the docker builds when all that changes is tests or documentation. The docker image strips out these files anyway.

However, the unit test flow still needs to run when these change to verify the formatting of markdown files and to run the tests.

Validation

Related Issues

Check List

• I confirm that my contribution is made under the terms of the Apache 2.0
  license.
• I have run pnpm checks to ensure code compiles and meets standards.
• I have run pnpm test to check if all tests are passing.
• I have covered new added functionality with unit tests if necessary.
• I have added an entry in the Changelog.md.