fix(deps): update dependency io.micronaut:micronaut-core-bom to v4.8.4 (#1192)

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

Author: renovate[bot]

gradle/libs.versions.toml

@@ -13,7 +13,7 @@ managed-bytebuddy = "1.17.0"
 graal-svm = "24.1.2"
 
 micronaut-platform = "4.7.6"
-micronaut = "4.8.3"
+micronaut = "4.8.4"
 micronaut-docs = "2.0.0"
 micronaut-test = "4.6.2"
 micronaut-data = "4.11.1"