chore(dependencies): bump Saxon-HE from 9.9.1-8 to 10.9 (#432)

according to the [Saxonica](https://www.saxonica.com), the authors of
`Saxon HE`, the v9 is no longer maintained. so lets upgrade.

> [...] current actively maintained versions of Saxon-HE:
[10](https://github.com/Saxonica/Saxon-HE/blob/main/10),
[11](https://github.com/Saxonica/Saxon-HE/blob/main/11), and
[12](https://github.com/Saxonica/Saxon-HE/blob/main/12).


tried to upgrade to v12 or v11 without success.
so i chose the latest successful version: v10.9

Author: stevespringett

docgen/xml/gen.sh

@@ -5,19 +5,27 @@ THIS_PATH="$(realpath "$(dirname "$0")")"
 SCHEMA_PATH="$(realpath "$THIS_PATH/../../schema")"
 DOCS_PATH="$THIS_PATH/docs"
 
-SAXON_JAR='Saxon-HE-9.9.1-8.jar'
+SAXON_VERSION='10.9'
 
-rm -f -R docs
+# --
+
+
+rm -rf "$DOCS_PATH"
+
+
+SAXON_JAR="Saxon-HE-${SAXON_VERSION}.jar"
 if [ ! -f "$THIS_PATH/$SAXON_JAR" ]; then
   curl --output-dir "$THIS_PATH" -O \
-    "https://repo1.maven.org/maven2/net/sf/saxon/Saxon-HE/9.9.1-8/$SAXON_JAR"
+    "https://repo1.maven.org/maven2/net/sf/saxon/Saxon-HE/$SAXON_VERSION/$SAXON_JAR"
 fi
 
+
 generate () {
   version="$1"
   title="CycloneDX v$version XML Reference"
   echo "Generating: $title"
 
+  ## docs: https://www.saxonica.com/documentation10/index.html#!using-xsl/commandline
   java -jar "$THIS_PATH/$SAXON_JAR" \
     -s:"$SCHEMA_PATH/bom-${version}.xsd" \
     -xsl:"$THIS_PATH/xs3p.xsl" \