diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 63e27b14..4de7bd0c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -64,12 +64,7 @@ jobs:
             10.0
       - name: Install mono on Linux
         if: runner.os == 'Linux'
-        # check https://www.mono-project.com/download/stable/#download-lin
         run: |
-          sudo apt install ca-certificates gnupg
-          sudo gpg --homedir /tmp --no-default-keyring --keyring gnupg-ring:/usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
-          sudo chmod +r /usr/share/keyrings/mono-official-archive-keyring.gpg
-          echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu stable-focal main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list
           sudo apt update
           sudo apt install -y mono-complete
           mono --version
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index d417ea3c..1c5b7722 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -11,7 +11,7 @@ on:
 jobs:
   analyze:
     name: Analyze
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
 
     strategy:
       fail-fast: false
@@ -37,12 +37,7 @@ jobs:
 
     - name: Install mono
       if: runner.os == 'Linux'
-      # check https://www.mono-project.com/download/stable/#download-lin
       run: |
-        sudo apt install ca-certificates gnupg
-        sudo gpg --homedir /tmp --no-default-keyring --keyring gnupg-ring:/usr/share/keyrings/mono-official-archive-keyring.gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
-        sudo chmod +r /usr/share/keyrings/mono-official-archive-keyring.gpg
-        echo "deb [signed-by=/usr/share/keyrings/mono-official-archive-keyring.gpg] https://download.mono-project.com/repo/ubuntu stable-focal main" | sudo tee /etc/apt/sources.list.d/mono-official-stable.list
         sudo apt update
         sudo apt install -y mono-complete
         mono --version