Update dependency no.nav.security:mock-oauth2-server to v0.5.4

Author: renovate[bot]

sigstore-java/build.gradle.kts

@@ -45,7 +45,7 @@ dependencies {
     testImplementation(platform("org.junit:junit-bom:5.9.1"))
     testImplementation("org.junit.jupiter:junit-jupiter")
 
-    testImplementation("no.nav.security:mock-oauth2-server:0.5.1")
+    testImplementation("no.nav.security:mock-oauth2-server:0.5.4")
     testImplementation("com.squareup.okhttp3:mockwebserver:4.10.0")
     testImplementation("net.sourceforge.htmlunit:htmlunit:2.64.0")
     testImplementation("org.eclipse.jetty:jetty-server:11.0.11")