patch 9.0.0401: CI uses older clang version

Problem:    CI uses older clang version.
Solution:   Switch from clang 14 to 15. (closes #11066)

.github/workflows/ci.yml

@@ -98,17 +98,17 @@ jobs:
           sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-11 100
           sudo update-alternatives --set gcc /usr/bin/gcc-11
 
-      - name: Install clang-14
+      - name: Install clang-15
         if: matrix.compiler == 'clang'
         run: |
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
           . /etc/lsb-release
-          sudo add-apt-repository -y "deb http://apt.llvm.org/${DISTRIB_CODENAME}/ llvm-toolchain-${DISTRIB_CODENAME}-14 main"
-          sudo apt install -y clang-14 llvm-14
-          sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-14 100
-          sudo update-alternatives --set clang /usr/bin/clang-14
-          sudo update-alternatives --install /usr/bin/llvm-cov llvm-cov /usr/bin/llvm-cov-14 100
-          sudo update-alternatives --install /usr/bin/asan_symbolize asan_symbolize /usr/bin/asan_symbolize-14 100
+          sudo add-apt-repository -y "deb http://apt.llvm.org/${DISTRIB_CODENAME}/ llvm-toolchain-${DISTRIB_CODENAME}-15 main"
+          sudo apt install -y clang-15 llvm-15
+          sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-15 100
+          sudo update-alternatives --set clang /usr/bin/clang-15
+          sudo update-alternatives --install /usr/bin/llvm-cov llvm-cov /usr/bin/llvm-cov-15 100
+          sudo update-alternatives --install /usr/bin/asan_symbolize asan_symbolize /usr/bin/asan_symbolize-15 100
 
       - name: Set up environment
         run: |

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    401,
 /**/
     400,
 /**/