Supporting gfortran 13

[zaikunzhang]

Hello @awvwgk !

First of all, thank the team for this wonderful work! I use this action multiple times each and every day for the PRIMA project. It is life-changing that Fortran compilers are made available on GitHub Actions so that I can automate the test and verification of my code, which are impossible on my local machines given the large amount and high frequency of the randomized experiments.

Now that gfortran-13 has been released, I am eager to test my project using this new version of the compiler. I understand that it takes time to support gfortran-13, and I look forward to seeing it implemented.

Many thanks and best regards,
Zaikun