CI: Use LLVM repo of correct Ubuntu versions

The Clang build jobs in htop's CI now grabs the Ubuntu codename
automatically from the /etc/os-release file of the Ubuntu image.
This frees us the need to update the codenames when the "ubuntu-latest"
image gets updated upstream (by GitHub).

At the time of the writing, the "ubuntu-latest" image contains
"ubuntu-24.04" (noble).

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>

Author: Explorer09

.github/workflows/ci.yml

@@ -36,8 +36,9 @@ jobs:
     - uses: actions/checkout@v4
     - name: install clang repo
       run: |
+        ubuntu_codename=`LC_ALL=C sed 's/^ *UBUNTU_CODENAME *= *\([a-z]*\).*$/\1/p; d' /etc/os-release`
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key 2>/dev/null | sudo apt-key add -
-        sudo add-apt-repository 'deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-18 main' -y
+        sudo add-apt-repository "deb http://apt.llvm.org/${ubuntu_codename}/ llvm-toolchain-${ubuntu_codename}-18 main" -y
         sudo apt-get update -q
     - name: Install Dependencies
       run: sudo apt-get install --no-install-recommends clang-18 libncursesw5-dev
@@ -77,8 +78,9 @@ jobs:
     - uses: actions/checkout@v4
     - name: install clang repo
       run: |
+        ubuntu_codename=`LC_ALL=C sed 's/^ *UBUNTU_CODENAME *= *\([a-z]*\).*$/\1/p; d' /etc/os-release`
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key 2>/dev/null | sudo apt-key add -
-        sudo add-apt-repository 'deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-18 main' -y
+        sudo add-apt-repository "deb http://apt.llvm.org/${ubuntu_codename}/ llvm-toolchain-${ubuntu_codename}-18 main" -y
         sudo apt-get update -q
     - name: Install Dependencies
       run: sudo apt-get install --no-install-recommends clang-18 libncursesw5-dev libhwloc-dev libnl-3-dev libnl-genl-3-dev libsensors-dev libcap-dev
@@ -146,8 +148,9 @@ jobs:
     - uses: actions/checkout@v4
     - name: install clang repo
       run: |
+        ubuntu_codename=`LC_ALL=C sed 's/^ *UBUNTU_CODENAME *= *\([a-z]*\).*$/\1/p; d' /etc/os-release`
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key 2>/dev/null | sudo apt-key add -
-        sudo add-apt-repository 'deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-18 main' -y
+        sudo add-apt-repository "deb http://apt.llvm.org/${ubuntu_codename}/ llvm-toolchain-${ubuntu_codename}-18 main" -y
         sudo apt-get update -q
     - name: Install Dependencies
       run: sudo apt-get install --no-install-recommends clang-18 clang-tools-18 libncursesw5-dev libnl-3-dev libnl-genl-3-dev libsensors-dev libcap-dev
@@ -172,8 +175,9 @@ jobs:
     - uses: actions/checkout@v4
     - name: install clang repo
       run: |
+        ubuntu_codename=`LC_ALL=C sed 's/^ *UBUNTU_CODENAME *= *\([a-z]*\).*$/\1/p; d' /etc/os-release`
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key 2>/dev/null | sudo apt-key add -
-        sudo add-apt-repository 'deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-18 main' -y
+        sudo add-apt-repository "deb http://apt.llvm.org/${ubuntu_codename}/ llvm-toolchain-${ubuntu_codename}-18 main" -y
         sudo apt-get update -q
     - name: Install LLVM Toolchain
       run: sudo apt-get install --no-install-recommends clang-18 libclang-rt-18-dev llvm-18