Bump jetty-server in /environments/servlet

Bumps [jetty-server](https://github.com/eclipse/jetty.project) from 9.4.35.v20201120 to 9.4.38.v20210224.
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.35.v20201120...jetty-9.4.38.v20210224)

Signed-off-by: dependabot[bot] <support@github.com>

environments/servlet/pom.xml

@@ -30,7 +30,7 @@
     <properties>
         <jsf.version>3.0.0</jsf.version>
         <tomcat.version>10.0.5</tomcat.version>
-        <jetty.version>9.4.35.v20201120</jetty.version>
+        <jetty.version>9.4.38.v20210224</jetty.version>
         <jetty9.asm.version>7.0</jetty9.asm.version>
         <websockets.api>2.0.0</websockets.api>
         <!-- We need undertow which uses Jakarta 9 packages! -->