Bump golang.org/x/oauth2 from 0.16.0 to 0.22.0

Bumps [golang.org/x/oauth2](https://github.com/golang/oauth2) from 0.16.0 to 0.22.0.
- [Commits](golang/oauth2@v0.16.0...v0.22.0)

---
updated-dependencies:
- dependency-name: golang.org/x/oauth2
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -5,14 +5,10 @@ go 1.17
 require (
 	github.com/google/go-github/v30 v30.1.0
 	github.com/kouhin/envflag v0.0.0-20150818174321-0e9a86061649
-	golang.org/x/oauth2 v0.16.0
+	golang.org/x/oauth2 v0.22.0
 )
 
 require (
-	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/go-querystring v1.0.0 // indirect
 	golang.org/x/crypto v0.18.0 // indirect
-	golang.org/x/net v0.20.0 // indirect
-	google.golang.org/appengine v1.6.7 // indirect
-	google.golang.org/protobuf v1.31.0 // indirect
 )