chore: add spotbugs

Author: AlexProgrammerDE

buildSrc/src/main/kotlin/pq.java-conventions.gradle.kts

@@ -2,6 +2,7 @@ plugins {
   `java-library`
   `maven-publish`
   id("net.ltgt.errorprone")
+  id("com.github.spotbugs")
 }
 
 java {
@@ -10,9 +11,15 @@ java {
   }
 }
 
+spotbugs {
+  ignoreFailures = true
+}
+
 dependencies {
   implementation("org.jetbrains:annotations:26.0.2-1")
+
   errorprone("com.google.errorprone:error_prone_core:2.43.0")
+  spotbugs("com.github.spotbugs:spotbugs:4.9.8")
 
   compileOnly("org.projectlombok:lombok:1.18.42")
   annotationProcessor("org.projectlombok:lombok:1.18.42")