build(deps): bump google.golang.org/grpc from 1.67.0 to 1.68.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.67.0 to 1.68.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.67.0...v1.68.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -1,7 +1,7 @@
 module github.com/tektoncd/pipeline
 
 go 1.22
-toolchain go1.22.5
+toolchain go1.22.9
 
 require (
 	github.com/Microsoft/go-winio v0.6.2 // indirect
@@ -26,7 +26,7 @@ require (
 	go.opencensus.io v0.24.0
 	go.uber.org/zap v1.27.0
 	golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc
-	golang.org/x/oauth2 v0.22.0 // indirect
+	golang.org/x/oauth2 v0.23.0 // indirect
 	gomodules.xyz/jsonpatch/v2 v2.4.0
 	k8s.io/api v0.29.6
 	k8s.io/apimachinery v0.29.7
@@ -133,8 +133,8 @@ require (
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.27.0 // indirect
 	go.opentelemetry.io/otel/metric v1.28.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.2.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20240814211410-ddb44dafa142 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240903143218-8af14fe29dc1 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 // indirect
 	gopkg.in/go-jose/go-jose.v2 v2.6.3 // indirect
 )
 
@@ -228,18 +228,18 @@ require (
 	github.com/vbatts/tar-split v0.11.3 // indirect
 	go.uber.org/automaxprocs v1.5.3 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
-	golang.org/x/crypto v0.26.0 // indirect
+	golang.org/x/crypto v0.27.0 // indirect
 	golang.org/x/mod v0.17.0 // indirect
-	golang.org/x/net v0.28.0 // indirect
+	golang.org/x/net v0.29.0 // indirect
 	golang.org/x/sync v0.8.0
-	golang.org/x/sys v0.24.0 // indirect
-	golang.org/x/term v0.23.0 // indirect
-	golang.org/x/text v0.17.0 // indirect
+	golang.org/x/sys v0.25.0 // indirect
+	golang.org/x/term v0.24.0 // indirect
+	golang.org/x/text v0.18.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
 	golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d // indirect
 	google.golang.org/api v0.181.0 // indirect
 	google.golang.org/genproto v0.0.0-20240401170217-c3f982113cda // indirect
-	google.golang.org/grpc v1.67.0
+	google.golang.org/grpc v1.68.0
 	google.golang.org/protobuf v1.34.2
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect