Bump snakeyaml from 1.29 to 1.31 in /ruby-tools

Bumps [snakeyaml](https://bitbucket.org/snakeyaml/snakeyaml) from 1.29 to 1.31.
- [Commits](https://bitbucket.org/snakeyaml/snakeyaml/branches/compare/snakeyaml-1.31..snakeyaml-1.29)

---
updated-dependencies:
- dependency-name: org.yaml:snakeyaml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

ruby-tools/pom.xml

@@ -60,7 +60,7 @@
     <dependency>
       <groupId>org.yaml</groupId>
       <artifactId>snakeyaml</artifactId>
-      <version>1.29</version>
+      <version>1.31</version>
     </dependency>
     <dependency>
       <groupId>org.apache.maven</groupId>