[SPARK-29445][CORE] Bump netty-all from 4.1.39.Final to 4.1.42.Final

### What changes were proposed in this pull request?

Minor version bump of Netty to patch reported CVE.

Patches: https://www.cvedetails.com/cve/CVE-2019-16869/

### Why are the changes needed?

### Does this PR introduce any user-facing change?

No

### How was this patch tested?

Compiled locally using `mvn clean install -DskipTests`

Closes #26099 from Fokko/SPARK-29445.

Authored-by: Fokko Driesprong <[email protected]>
Signed-off-by: Sean Owen <[email protected]>

Author: Fokko

dev/deps/spark-deps-hadoop-2.7

@@ -154,7 +154,7 @@ metrics-graphite-3.1.5.jar
 metrics-json-3.1.5.jar
 metrics-jvm-3.1.5.jar
 minlog-1.3.0.jar
-netty-all-4.1.39.Final.jar
+netty-all-4.1.42.Final.jar
 objenesis-2.5.1.jar
 okapi-shade-0.4.2.jar
 okhttp-3.8.1.jar

dev/deps/spark-deps-hadoop-3.2

@@ -170,7 +170,7 @@ metrics-json-3.1.5.jar
 metrics-jvm-3.1.5.jar
 minlog-1.3.0.jar
 mssql-jdbc-6.2.1.jre7.jar
-netty-all-4.1.39.Final.jar
+netty-all-4.1.42.Final.jar
 nimbus-jose-jwt-4.41.1.jar
 objenesis-2.5.1.jar
 okapi-shade-0.4.2.jar

pom.xml

@@ -658,7 +658,7 @@
       <dependency>
         <groupId>io.netty</groupId>
         <artifactId>netty-all</artifactId>
-        <version>4.1.39.Final</version>
+        <version>4.1.42.Final</version>
       </dependency>
       <dependency>
         <groupId>org.apache.derby</groupId>