Bump guava from 20.0 to 23.0 (#957)

Bumps [guava](https://github.com/google/guava) from 20.0 to 23.0.
- [Release notes](https://github.com/google/guava/releases)
- [Commits](google/guava@v20.0...v23.0)

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

elide-standalone/pom.xml

@@ -85,7 +85,7 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>27.1-jre</version>
+            <version>23.0</version>
         </dependency>
 
         <!-- Hibernate -->

pom.xml

@@ -125,7 +125,7 @@
             <dependency>
                 <groupId>com.google.guava</groupId>
                 <artifactId>guava</artifactId>
-                <version>20.0</version>
+                <version>23.0</version>
             </dependency>
             <dependency>
                 <groupId>javax.inject</groupId>