patch 9.0.1253: CI adds repository unnecessarily

Problem:    CI adds repository unnecessarily.
Solution:   Remove the line from the workflow. (closes #11900)

.github/workflows/ci.yml

@@ -96,7 +96,6 @@ jobs:
       - name: Install gcc-11
         if:  matrix.compiler == 'gcc'
         run: |
-          sudo add-apt-repository ppa:ubuntu-toolchain-r/test
           sudo apt install -y gcc-11
           sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 100
           sudo update-alternatives --set gcc /usr/bin/gcc-11

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1253,
 /**/
     1252,
 /**/