fix(deps): update dependency org.mockito:mockito-bom to v5.5.0

Author: renovate[bot]

sigstore-java/build.gradle.kts

@@ -49,7 +49,7 @@ dependencies {
     testImplementation(platform("org.junit:junit-bom:5.10.0"))
     testImplementation("org.junit.jupiter:junit-jupiter")
 
-    testImplementation(platform("org.mockito:mockito-bom:5.1.1"))
+    testImplementation(platform("org.mockito:mockito-bom:5.5.0"))
     testImplementation("org.mockito:mockito-core")
     testImplementation("org.mockito:mockito-junit-jupiter")