[ci] add XML lint to dependency; enable xml format in CI

.github/workflows/format.yaml

@@ -19,6 +19,8 @@ jobs:
         config:
           - name: "C/C++"
             code_type: "-cpp"
+          - name: "XML"
+            code_type: "-xml"
     steps:
       - name: Cancel previous
         uses: styfle/cancel-workflow-action@0.9.1

.github/workflows/install_dependencies_build.sh

@@ -59,4 +59,5 @@ sudo apt-get install -y \
     clang-7 \
     clang-8 \
     clang-10 \
-    clang-format-10
+    clang-format-10 \
+    libxml2-utils