build(deps): bump go.elastic.co/fastjson from 1.3.0 to 1.4.0

Bumps [go.elastic.co/fastjson](https://github.com/elastic/go-fastjson) from 1.3.0 to 1.4.0.
- [Release notes](https://github.com/elastic/go-fastjson/releases)
- [Commits](elastic/go-fastjson@v1.3.0...v1.4.0)

---
updated-dependencies:
- dependency-name: go.elastic.co/fastjson
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -10,7 +10,7 @@ require (
 	go.elastic.co/apm/module/apmelasticsearch/v2 v2.6.0
 	go.elastic.co/apm/module/apmzap/v2 v2.6.0
 	go.elastic.co/apm/v2 v2.6.0
-	go.elastic.co/fastjson v1.3.0
+	go.elastic.co/fastjson v1.4.0
 	go.opentelemetry.io/otel v1.29.0
 	go.opentelemetry.io/otel/metric v1.29.0
 	go.opentelemetry.io/otel/sdk v1.29.0

go.sum

@@ -61,8 +61,8 @@ go.elastic.co/apm/module/apmzap/v2 v2.6.0 h1:R/iVORzGu3F9uM43iEVHD0nwiRo59O0bIXd
 go.elastic.co/apm/module/apmzap/v2 v2.6.0/go.mod h1:B3i/8xRkqLgi6zNuV+Bp7Pt4cutaOObvrVSa7wUTAPw=
 go.elastic.co/apm/v2 v2.6.0 h1:VieBMLQFtXua2YxpYxaSdYGnmmxhLT46gosI5yErJgY=
 go.elastic.co/apm/v2 v2.6.0/go.mod h1:33rOXgtHwbgZcDgi6I/GtCSMZQqgxkHC0IQT3gudKvo=
-go.elastic.co/fastjson v1.3.0 h1:hJO3OsYIhiqiT4Fgu0ZxAECnKASbwgiS+LMW5oCopKs=
-go.elastic.co/fastjson v1.3.0/go.mod h1:K9vDh7O0ODsVKV2B5e2XYLY277QZaCbB3tS1SnARvko=
+go.elastic.co/fastjson v1.4.0 h1:a4BXUKXZHAzjVOPrqtEx2FDsIRBCMek01vCnrtyutWs=
+go.elastic.co/fastjson v1.4.0/go.mod h1:ZD5um63l0/8TIdddZbL2znD83FAr2IckYa3KR7VcdNA=
 go.opentelemetry.io/otel v1.29.0 h1:PdomN/Al4q/lN6iBJEN3AwPvUiHPMlt93c8bqTG5Llw=
 go.opentelemetry.io/otel v1.29.0/go.mod h1:N/WtXPs1CNCUEx+Agz5uouwCba+i+bJGFicT8SR4NP8=
 go.opentelemetry.io/otel/metric v1.29.0 h1:vPf/HFWTNkPu1aYeIsc98l4ktOQaL6LeSoeV2g+8YLc=