Change method resolveSigningKey from class to interface

The resolveSigningKey method of SigningKeyResolverAdapter is an
implementation of that defined in SigningKeyResolver. So this changes
the type from the class to the interface it implements

Author: egregius313

java/ql/lib/ext/io.jsonwebtoken.model.yml

@@ -11,5 +11,5 @@ extensions:
       pack: codeql/java-all
       extensible: sourceModel
     data:
-      - ["io.jsonwebtoken", "SigningKeyResolverAdapter", True, "resolveSigningKey", "", "", "Parameter[0]", "remote", "manual"]
+      - ["io.jsonwebtoken", "SigningKeyResolver", True, "resolveSigningKey", "", "", "Parameter[0]", "remote", "manual"]
       - ["io.jsonwebtoken", "SigningKeyResolverAdapter", True, "resolveSigningKeyBytes", "", "", "Parameter[0]", "remote", "manual"]