Addition of GCC 13 to CI (#737)

* Addition of GCC 13 to CI

* update README.md for GCC compilers

Author: jvdp1

.github/workflows/CI.yml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-        gcc_v: [10, 11, 12] # Version of GFortran we want to use.
+        gcc_v: [10, 11, 12, 13] # Version of GFortran we want to use.
         build: [cmake]
         include:
           - os: ubuntu-latest

README.md

@@ -87,8 +87,8 @@ The following combinations are tested on the default branch of stdlib:
 
 Name | Version | Platform | Architecture
 --- | --- | --- | ---
-GCC Fortran | 10, 11, 12 | Ubuntu 22.04.2 LTS | x86_64
-GCC Fortran | 10, 11, 12 | macOS 12.6.3 (21G419) | x86_64
+GCC Fortran | 10, 11, 12, 13 | Ubuntu 22.04.2 LTS | x86_64
+GCC Fortran | 10, 11, 12, 13 | macOS 12.6.3 (21G419) | x86_64
 GCC Fortran (MSYS) | 10 | Windows Server 2022 (10.0.20348 Build 1547) | x86_64
 GCC Fortran (MinGW) | 10 | Windows Server 2022 (10.0.20348 Build 1547) | x86_64, i686
 Intel oneAPI classic | 2021.1 | Ubuntu 22.04.2 LTS | x86_64