deps: update doclet version to v1.9.0 (#1211)

Author: alicejli

pom.xml

@@ -478,7 +478,7 @@
  </activation>
  <properties>
  <!-- default config values -->
- <docletName>java-docfx-doclet-1.5.0</docletName>
+ <docletName>java-docfx-doclet-1.9.0</docletName>
  <outputpath>${project.build.directory}/docfx-yml</outputpath>
  <projectname>${project.artifactId}</projectname>
  <excludeclasses></excludeclasses>