fix: upgrade org.slf4j:slf4j-api from 1.7.21 to 1.7.32

Snyk has created this PR to upgrade org.slf4j:slf4j-api from 1.7.21 to 1.7.32.

See this package in Maven Repository:
https://mvnrepository.com/artifact/org.slf4j/slf4j-api/

See this project in Snyk:
https://app.snyk.io/org/salesforce-oss/project/209e1852-f8b9-474c-8c46-c654cb699b6a?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

contrib/pom.xml

@@ -61,7 +61,7 @@
         <!-- Dependency Versions -->
         <grpc.version>1.24.0</grpc.version>
         <protoc.version>3.9.1</protoc.version> <!-- Same version as grpc-proto -->
-        <slf4j.version>1.7.21</slf4j.version>
+        <slf4j.version>1.7.32</slf4j.version>
         <gson.version>2.7</gson.version> <!-- Same version as grpc-proto -->
         <mustache-java.version>0.9.4</mustache-java.version>
         <spring.version>4.2.0.RELEASE</spring.version>