chore: add suppression for spotbugs nullable warn

Ref: spotbugs/spotbugs 616

Author: dnwe

src/main/java/org/jenkinsci/plugins/github/util/misc/NullSafeFunction.java

@@ -14,6 +14,10 @@
 public abstract class NullSafeFunction<F, T> implements Function<F, T> {
 
     @Override
+    @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(
+        value = "NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE",
+        justification = "https://github.com/spotbugs/spotbugs/issues/616"
+    )
     public T apply(F input) {
         return applyNullSafe(checkNotNull(input, "This function does not allow using null as argument"));
     }

src/main/java/org/jenkinsci/plugins/github/util/misc/NullSafePredicate.java

@@ -15,6 +15,10 @@
 public abstract class NullSafePredicate<T> implements Predicate<T> {
 
     @Override
+    @edu.umd.cs.findbugs.annotations.SuppressFBWarnings(
+        value = "NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE",
+        justification = "https://github.com/spotbugs/spotbugs/issues/616"
+    )
     public boolean apply(T input) {
         return applyNullSafe(checkNotNull(input, "Argument for this predicate can't be null"));
     }