fix(deps): update dependency io.micronaut:micronaut-core-bom to v4.9.4 (#1012)

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

Author: renovate[bot]

gradle/libs.versions.toml

@@ -1,6 +1,6 @@
 [versions]
 micronaut-platform = "4.8.3"
-micronaut = "4.9.3"
+micronaut = "4.9.4"
 micronaut-docs = "2.0.0"
 micronaut-gradle-plugin = "4.5.3"
 micronaut-test = "4.7.0"