Ignore baseline prior to 4.2.0 for two overridden Schema methods

Add `BaselineIgnore` annotation to Schema methods addExtension and
extensions for versions prior to 4.2.0. These methods were
added/overridden in Schema from Extensible to refine/clarify specific
details about how they behave on Schema.

This is required because the bnd-baseline Maven plugin believes these
methods to be breaking API changes due to the change of return type from
a generic type in `Extensible` to `Schema` in the overrides.

Signed-off-by: Michael Edgar <michael@xlate.io>

Author: MikeEdgar

api/pom.xml

@@ -33,6 +33,12 @@
             <artifactId>osgi.annotation</artifactId>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>biz.aQute.bnd</groupId>
+            <artifactId>biz.aQute.bnd.annotation</artifactId>
+            <version>7.0.0</version>
+            <scope>provided</scope>
+        </dependency>
     </dependencies>
 
     <build>

api/src/main/java/module-info.java

@@ -52,5 +52,5 @@
 
     // Required for compilation, not used at runtime
     requires static osgi.annotation;
-
+    requires static biz.aQute.bnd.annotation;
 }

api/src/main/java/org/eclipse/microprofile/openapi/models/media/Schema.java

@@ -2167,6 +2167,7 @@ default Schema examples(List<Object> examples) {
      * @see <a href="#schema-extensions">Schema Extensions</a>
      */
     @Override
+    @aQute.bnd.annotation.baseline.BaselineIgnore("4.2.0")
     default Schema extensions(Map<String, Object> extensions) {
         return Extensible.super.extensions(extensions);
     }
@@ -2184,6 +2185,7 @@ default Schema extensions(Map<String, Object> extensions) {
      * @see <a href="#schema-extensions">Schema Extensions</a>
      */
     @Override
+    @aQute.bnd.annotation.baseline.BaselineIgnore("4.2.0")
     Schema addExtension(String name, Object value);
 
     /**