Improve Wording of Lint Checker

Currently the lint checker checks for version increments when code has changed, the error wording reads: Code update without version change. This gives little help as to which version file needs to be incremented.

This could be changed to read Code has been updated without a version change. Check the current version of file [version.txt|_version.py] in main and ensure you have incremented the version

This would make it easier for new contributors to the repo to understand which versions need bumping when they've made changes.
Links to files below:
build_docker_images.yml
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_docker_images.yml#L67)
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_docker_images.yml#L72)
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_docker_images.yml#L77)
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_docker_images.yml#L82)
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_docker_images.yml#L87)
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_docker_images.yml#L92),
build_validation_develop.yml
(https://github.com/microsoft/AzureTRE/blob/6d51070b7cffb9b38219e860bf48c9450dfc9071/.github/workflows/build_validation_develop.yml#L81)

Start with the lint-checker steps linked in .github/workflows/build_docker_images.yml and .github/workflows/build_validation_develop.yml, then locate the code that emits “Code update without version change.” Update the message to identify version.txt and _version.py and explain the required increment; done means the checker reports the clearer wording when code changes without a version bump.