AT2 CI Build Version Upgrade -- gcc-serial

[achauphan]

The current required gcc-serial GitHub Action check, gcc-830, will be upgraded to the gcc-14 job on 10-14-2025.

The gcc-14 job was added on 08-14-2025 (PR#14291) to replace the current gcc-830 job, and has been in a stable enough spot to warrant this transition.

If you encounter any issues that you think are related to this change, please open an issue and tag @trilinos/framework.

[achauphan]

Updated branch rules for master and develop:

• removed required gcc830 check
• added required gcc14 check

[achauphan]

#14566 merged into develop removing the GitHub Actions job. A spawner for the gcc-8.3.0 runner will still be active on our machines for the specific case of maintaining coverage for the trilinos-release-16-1-branch which had the job as required.