Upgrade Forbidden APIs plugin 3.7 -> 3.8 (#1355)

See:
- https://github.com/policeman-tools/forbidden-apis/wiki/Changes
- policeman-tools/forbidden-apis@3.7...3.8

pom.xml

@@ -587,7 +587,7 @@
                 <plugin>
                     <groupId>de.thetaphi</groupId>
                     <artifactId>forbiddenapis</artifactId>
-                    <version>3.7</version>
+                    <version>3.8</version>
                     <configuration>
                         <bundledSignatures>
                             <bundledSignature>jdk-internal</bundledSignature>