patch 9.0.1562: mixing package managers is not a good idea

Problem:    Mixing package managers is not a good idea.
Solution:   Install gcc 13 with apt-get. (closes #12405)
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bd903dc..4e6f23b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,7 +21,7 @@
 
     env:
       CC: ${{ matrix.compiler }}
-      GCC_VER: 12
+      GCC_VER: 13
       CLANG_VER: 16
       TEST: test
       SRCDIR: ./src
@@ -98,10 +98,9 @@
       - name: Install gcc-${{ env.GCC_VER }}
         if:  matrix.compiler == 'gcc'
         run: |
-          eval "$(/home/linuxbrew/.linuxbrew/bin/brew shellenv)"
-          brew install gcc@${{ env.GCC_VER }}
-          sudo update-alternatives --install /usr/bin/gcc gcc /home/linuxbrew/.linuxbrew/bin/gcc-${{ env.GCC_VER }} 100
-          sudo update-alternatives --set gcc /home/linuxbrew/.linuxbrew/bin/gcc-${{ env.GCC_VER }}
+          sudo apt-get install -y gcc-${{ env.GCC_VER }}
+          sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-${{ env.GCC_VER }} 100
+          sudo update-alternatives --set gcc /usr/bin/gcc-${{ env.GCC_VER }}
 
       - name: Install clang-${{ env.CLANG_VER }}
         if: matrix.compiler == 'clang'
diff --git a/src/version.c b/src/version.c
index 9f64843..80244d6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1562,
+/**/
     1561,
 /**/
     1560,