Compile jakarta variant as Java 8

Signed-off-by: Ben Hale <bhale@vmware.com>

Author: nebhale

java-buildpack-client-certificate-mapper-jakarta/pom.xml

@@ -82,8 +82,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>17</source>
-                    <target>17</target>
+                    <source>8</source>
+                    <target>8</target>
                 </configuration>
             </plugin>
             <plugin>