Bump gruf from 2.20.1 to 2.21.0 in /web

Bumps [gruf](https://github.com/bigcommerce/gruf) from 2.20.1 to 2.21.0.
- [Release notes](https://github.com/bigcommerce/gruf/releases)
- [Changelog](https://github.com/bigcommerce/gruf/blob/main/CHANGELOG.md)
- [Commits](bigcommerce/gruf@v2.20.1...v2.21.0)

---
updated-dependencies:
- dependency-name: gruf
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

web/Gemfile

@@ -91,7 +91,7 @@ gem "flipper-active_record"
 gem "flipper-ui", "~> 1.3"
 
 gem "grpc", "~> 1.69"
-gem "gruf", "~> 2.20.1"
+gem "gruf", "~> 2.21.0"
 gem "grpc-tools"
 
 gem "groupdate", "~> 6.5.1"

web/Gemfile.lock

@@ -235,7 +235,7 @@ GEM
       google-protobuf (>= 3.25, < 5.0)
       googleapis-common-protos-types (~> 1.0)
     grpc-tools (1.69.0)
-    gruf (2.20.1)
+    gruf (2.21.0)
       activesupport (> 4)
       concurrent-ruby (> 1)
       grpc (~> 1.10)
@@ -603,7 +603,7 @@ DEPENDENCIES
   groupdate (~> 6.5.1)
   grpc (~> 1.69)
   grpc-tools
-  gruf (~> 2.20.1)
+  gruf (~> 2.21.0)
   gruf-rspec (~> 1.0)
   hotwire-livereload (~> 2.0)
   importmap-rails