250813.092519.CST [skip ci] revise test_gfortran to include gfortran-12

Author: zaikunzhang

.github/workflows/test_gfortran.yml

@@ -29,7 +29,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-13, macos-latest]
         compiler: [gcc]
-        version: [13, 14]  # Too expensive to test all versions
+        version: [12, 13, 14]  # Too expensive to test all versions
         ikind: [i2, i8]
         solver: [newuoa, cobyla, lincoa, bobyqa, uobyqa]