CI: Build on Ubuntu 18.04, use newer clang-format

There are too many issues with 20.04 to successfully build with
VirtualCam - the azure kernel is missing videodev headers. For now,
use 18.04 LTS directly for main CI builds.

Both 18.04 and 20.04 include clang-format-10 without issue.

.github/workflows/clang-format.yml

@@ -13,18 +13,7 @@ jobs:
 
       - name: Install clang format
         run: |
-          # gets us newer clang
-          sudo bash -c "cat >> /etc/apt/sources.list" << LLVMAPT
-          # 3.8
-          deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-8 main
-          deb-src http://apt.llvm.org/xenial/ llvm-toolchain-xenial-8 main
-          LLVMAPT
-
-          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
-
-          sudo apt-get -qq update
-
-          sudo apt-get install -y clang-format-8
+          sudo apt-get install -y clang-format-10
 
       - name: Check the Formatting
         run: |

.github/workflows/main.yml

@@ -352,7 +352,7 @@ jobs:
           path: ./release/*.dmg
   ubuntu64:
     name: 'Linux/Ubuntu 64-bit'
-    runs-on: [ubuntu-latest]
+    runs-on: [ubuntu-18.04]
     steps:
       - name: 'Checkout'
         uses: actions/checkout@v2.3.3

formatcode.sh

@@ -19,7 +19,9 @@ if [[ $OS = "Linux" || $OS = "Darwin" ]] ; then
 fi
 
 # Discover clang-format
-if type clang-format-8 2> /dev/null ; then
+if type clang-format-10 2> /dev/null ; then
+    CLANG_FORMAT=clang-format-10
+elif type clang-format-8 2> /dev/null ; then
     CLANG_FORMAT=clang-format-8
 else
     CLANG_FORMAT=clang-format