Checkstyle fixes for webauthn JSpecify

Issue gh-17839

Signed-off-by: M.Bozorgmehr <mehrdad.bozorgmehr@gmail.com>

Author: rwinch

webauthn/src/main/java/org/springframework/security/web/webauthn/management/RelyingPartyRegistrationRequest.java

@@ -16,8 +16,6 @@
 
 package org.springframework.security.web.webauthn.management;
 
-import org.jspecify.annotations.Nullable;
-
 import org.springframework.security.web.webauthn.api.PublicKeyCredentialCreationOptions;
 
 /**

webauthn/src/main/java/org/springframework/security/web/webauthn/management/WebAuthnRelyingPartyOperations.java

@@ -16,8 +16,6 @@
 
 package org.springframework.security.web.webauthn.management;
 
-import org.jspecify.annotations.Nullable;
-
 import org.springframework.security.core.Authentication;
 import org.springframework.security.web.webauthn.api.CredentialRecord;
 import org.springframework.security.web.webauthn.api.PublicKeyCredentialCreationOptions;