CI: Remove flaky packages.microsoft.com Ubuntu repository

We don't need it.

.github/workflows/linux_builds.yml

@@ -78,8 +78,8 @@ jobs:
       - name: Linux dependencies for tests
         if: ${{ matrix.proj-test }}
         run: |
+          sudo rm -f /etc/apt/sources.list.d/microsoft-prod.list
           sudo add-apt-repository ppa:kisak/kisak-mesa
-          sudo apt-get update
           sudo apt-get install -qq mesa-vulkan-drivers
 
       - name: Setup Godot build cache

.github/workflows/static_checks.yml

@@ -15,9 +15,9 @@ jobs:
 
       - name: Install dependencies
         run: |
+          sudo rm -f /etc/apt/sources.list.d/microsoft-prod.list
           wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
           sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-15 main"
-          sudo apt-get update
           sudo apt-get install -qq dos2unix clang-format-15 libxml2-utils python3-pip moreutils
           sudo update-alternatives --remove-all clang-format || true
           sudo update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-15 100