Update JRuby 9.2.19.0 -> 9.2.20.1 and 9.3.0.0 to 9.3.3.0.

kokoro/linux/dockerfile/test/ruby/Dockerfile

diff --git a/kokoro/linux/dockerfile/test/ruby/Dockerfile b/kokoro/linux/dockerfile/test/ruby/Dockerfile
index 8362870..cfdc5ba 100644
--- a/kokoro/linux/dockerfile/test/ruby/Dockerfile
+++ b/kokoro/linux/dockerfile/test/ruby/Dockerfile
@@ -35,8 +35,8 @@
 RUN /bin/bash -l -c "rvm install 2.6.0"
 RUN /bin/bash -l -c "rvm install 2.7.0"
 RUN /bin/bash -l -c "rvm install 3.0.0"
-RUN /bin/bash -l -c "rvm install jruby-9.2.19.0"
-RUN /bin/bash -l -c "rvm install jruby-9.3.0.0"
+RUN /bin/bash -l -c "rvm install jruby-9.2.20.1"
+RUN /bin/bash -l -c "rvm install jruby-9.3.3.0"
 
 RUN /bin/bash -l -c "echo 'gem: --no-ri --no-rdoc' > ~/.gemrc"
 RUN /bin/bash -l -c "echo 'export PATH=/usr/local/rvm/bin:$PATH' >> ~/.bashrc"

ruby/pom.xml

diff --git a/ruby/pom.xml b/ruby/pom.xml
index c9ae9e6..7fd164a 100644
--- a/ruby/pom.xml
+++ b/ruby/pom.xml
@@ -81,7 +81,7 @@
         <dependency>
             <groupId>org.jruby</groupId>
             <artifactId>jruby-complete</artifactId>
-            <version>9.2.19.0</version>
+            <version>9.2.20.1</version>
             <scope>provided</scope>
         </dependency>
     </dependencies>

tests.sh

diff --git a/tests.sh b/tests.sh
index 8ea5ae6..d9047c4 100755
--- a/tests.sh
+++ b/tests.sh
@@ -426,13 +426,13 @@
 build_jruby92() {
   internal_build_cpp                # For conformance tests.
   internal_build_java jdk8 && cd .. # For Maven protobuf jar with local changes
-  cd ruby && bash travis-test.sh jruby-9.2.19.0 && cd ..
+  cd ruby && bash travis-test.sh jruby-9.2.20.1 && cd ..
 }
 
 build_jruby93() {
   internal_build_cpp                # For conformance tests.
   internal_build_java jdk8 && cd .. # For Maven protobuf jar with local changes
-  cd ruby && bash travis-test.sh jruby-9.3.0.0 && cd ..
+  cd ruby && bash travis-test.sh jruby-9.3.3.0 && cd ..
 }
 
 build_javascript() {