Update plugin spring-nullability to v0.0.6 (#419)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -15,4 +15,4 @@ telegram-bot-api = "com.github.pengrad:java-telegram-bot-api:9.2.0"
 tika = "org.apache.tika:tika-core:3.2.3"
 
 [plugins]
-spring-nullability = "io.spring.nullability:0.0.5"
+spring-nullability = "io.spring.nullability:0.0.6"