Upgrade Checker Framework Annotations 3.27.0 -> 3.28.0 (#382)

See:
- https://github.com/typetools/checker-framework/releases/tag/checker-framework-3.28.0
- typetools/checker-framework@checker-framework-3.27.0...checker-framework-3.28.0

pom.xml

@@ -343,7 +343,7 @@
             <dependency>
                 <groupId>org.checkerframework</groupId>
                 <artifactId>checker-qual</artifactId>
-                <version>3.27.0</version>
+                <version>3.28.0</version>
             </dependency>
             <dependency>
                 <groupId>org.hamcrest</groupId>