patch 9.0.1253: CI adds repository unnecessarily

Problem:    CI adds repository unnecessarily.
Solution:   Remove the line from the workflow. (closes #11900)
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 01cc16a..00ef41f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -96,7 +96,6 @@
       - 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
diff --git a/src/version.c b/src/version.c
index 89017e0..08947ca 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1253,
+/**/
     1252,
 /**/
     1251,