Improve tests to run on arm64 & smoketest seshat (#1668)

.github/workflows/build_and_test.yaml

@@ -104,7 +104,7 @@ jobs:
             matrix:
                 include:
                     - name: macOS Universal
-                      os: macos
+                      os: macos-latest
                       artifact: macos
                       executable: "/Users/runner/Applications/Element.app/Contents/MacOS/Element"
                       # We need to mount the DMG and copy the app to the Applications folder as a mounted DMG is
@@ -114,26 +114,41 @@ jobs:
                           rsync -a /Volumes/Element/Element.app ~/Applications/ &&
                           hdiutil detach /Volumes/Element
                     - name: "Linux (amd64) (sqlcipher: system)"
-                      os: ubuntu
+                      os: ubuntu-latest
                       artifact: linux-amd64-sqlcipher-system
                       executable: "/opt/Element/element-desktop"
                       prepare_cmd: "sudo apt install ./dist/*.deb"
                     - name: "Linux (amd64) (sqlcipher: static)"
-                      os: ubuntu
+                      os: ubuntu-latest
                       artifact: linux-amd64-sqlcipher-static
                       executable: "/opt/Element/element-desktop"
                       prepare_cmd: "sudo apt install ./dist/*.deb"
+                    - name: "Linux (arm64) (sqlcipher: system)"
+                      os: dind-l-arm64
+                      artifact: linux-arm64-sqlcipher-system
+                      executable: "/opt/Element/element-desktop"
+                      prepare_cmd: "sudo apt install -y ./dist/*.deb"
                     - name: Windows (x86)
-                      os: windows
+                      os: windows-latest
                       artifact: win-ia32
                       executable: "./dist/win-ia32-unpacked/Element.exe"
                     - name: Windows (x64)
-                      os: windows
+                      os: windows-latest
                       artifact: win-x64
                       executable: "./dist/win-unpacked/Element.exe"
         name: Test ${{ matrix.name }}
-        runs-on: ${{ matrix.os }}-latest
+        runs-on: ${{ matrix.os }}
         steps:
+            # Workaround for self-hosted runners lacking yarn
+            - name: Install Yarn
+              if: runner.environment == 'self-hosted'
+              run: |
+                  sudo apt-get -qq update
+                  sudo apt-get install -y curl
+                  curl -fsSL --create-dirs -o $HOME/bin/yarn https://github.com/yarnpkg/yarn/releases/download/v1.22.19/yarn-1.22.19.js
+                  chmod +x $HOME/bin/yarn
+                  echo "$HOME/bin" >> $GITHUB_PATH
+
             - uses: actions/checkout@v4
 
             - uses: actions/setup-node@v4