No longer run https://apt.llvm.org/llvm.sh

The ubuntu-26.04 image already provides required LLVM 21.

Author: vstinner

.github/workflows/jit.yml

@@ -160,8 +160,7 @@ jobs:
           sudo ./.github/workflows/posix-deps-apt.sh
       - name: Build
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM_VERSION }}
-          export PATH="$(llvm-config-${{ env.LLVM_VERSION }} --bindir):$PATH"
+          # On ubuntu-26.04 image, clang is clang-21 by default
           ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '' }}
           make all --jobs 4
       - name: Test
@@ -202,8 +201,7 @@ jobs:
           sudo ./.github/workflows/posix-deps-apt.sh
       - name: Build
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM_VERSION }}
-          export PATH="$(llvm-config-${{ env.LLVM_VERSION }} --bindir):$PATH"
+          # On ubuntu-26.04 image, clang is clang-21 by default
           if [ "${{ matrix.use_clang }}" = "true" ]; then
             export CC=clang-${{ env.LLVM_VERSION }}
           fi

.github/workflows/reusable-san.yml

@@ -37,14 +37,7 @@ jobs:
     - name: Install dependencies
       run: |
         sudo ./.github/workflows/posix-deps-apt.sh
-        # Install clang
-        wget https://apt.llvm.org/llvm.sh
-        chmod +x llvm.sh
-        sudo ./llvm.sh 21
-        sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-21 100
-        sudo update-alternatives --set clang /usr/bin/clang-21
-        sudo update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-21 100
-        sudo update-alternatives --set clang++ /usr/bin/clang++-21
+        # On ubuntu-26.04 image, clang is clang-21 by default
 
         if [ "${SANITIZER}" = "TSan" ]; then
           # Reduce ASLR to avoid TSan crashing

.github/workflows/reusable-ubuntu.yml

@@ -49,7 +49,7 @@ jobs:
     - name: Install Clang and BOLT
       if: ${{ fromJSON(inputs.bolt-optimizations) }}
       run: |
-        sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh 21
+        # On ubuntu-26.04 image, LLVM is LLVM-21 by default
         sudo apt-get install --no-install-recommends bolt-21
         echo PATH="$(llvm-config-21 --bindir):$PATH" >> $GITHUB_ENV
     - name: Configure OpenSSL env vars

.github/workflows/tail-call.yml

@@ -83,8 +83,7 @@ jobs:
           python-version: '3.11'
       - name: Build
         run: |
-          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM_VERSION }}
-          export PATH="$(llvm-config-${{ env.LLVM_VERSION }} --bindir):$PATH"
+          # On ubuntu-26.04 image, clang is clang-21 by default
           CC=clang-${{ env.LLVM_VERSION }} ./configure --with-tail-call-interp ${{ matrix.configure_flags }}
           make all --jobs 4
       - name: Test