chore(deps): bump build_runner from 2.4.6 to 2.4.9 (#1361)

Bumps [build_runner](https://github.com/dart-lang/build) from 2.4.6 to 2.4.9.
- [Release notes](https://github.com/dart-lang/build/releases)
- [Commits](https://github.com/dart-lang/build/compare/build_runner-v2.4.6...build_runner-v2.4.9)

---
updated-dependencies:
- dependency-name: build_runner
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pubspec.lock

@@ -277,10 +277,10 @@ packages:
     dependency: "direct dev"
     description:
       name: build_runner
-      sha256: "10c6bcdbf9d049a0b666702cf1cee4ddfdc38f02a19d35ae392863b47519848b"
+      sha256: "3ac61a79bfb6f6cc11f693591063a7f19a7af628dc52f141743edac5c16e8c22"
       url: "https://pub.dev"
     source: hosted
-    version: "2.4.6"
+    version: "2.4.9"
   build_runner_core:
     dependency: transitive
     description:

pubspec.yaml

@@ -131,7 +131,7 @@ dependencies:
   lrc: ^1.0.2
 
 dev_dependencies:
-  build_runner: ^2.3.2
+  build_runner: ^2.4.9
   envied_generator: ^0.3.0+3
   flutter_distributor: ^0.0.2
   flutter_gen_runner: ^5.1.0+1