Bump golang.org/x/oauth2 from 0.20.0 to 0.21.0 (#34)

Bumps [golang.org/x/oauth2](https://github.com/golang/oauth2) from 0.20.0 to 0.21.0.
- [Commits](golang/oauth2@v0.20.0...v0.21.0)

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

go.mod

@@ -5,7 +5,7 @@ go 1.21.3
 require (
  github.com/google/go-github/v56 v56.0.0
  github.com/hashicorp/go-version v1.2.1
- golang.org/x/oauth2 v0.20.0
+ golang.org/x/oauth2 v0.21.0
 )
 
 require github.com/google/go-querystring v1.1.0 // indirect

go.sum

@@ -7,6 +7,6 @@ github.com/google/go-github/v56 v56.0.0 h1:TysL7dMa/r7wsQi44BjqlwaHvwlFlqkK8CtBW
 github.com/google/go-github/v56 v56.0.0/go.mod h1:D8cdcX98YWJvi7TLo7zM4/h8ZTx6u6fwGEkCdisopo0=
 github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
 github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
-golang.org/x/oauth2 v0.20.0 h1:4mQdhULixXKP1rwYBW0vAijoXnkTG0BLCDRzfe1idMo=
-golang.org/x/oauth2 v0.20.0/go.mod h1:XYTD2NtWslqkgxebSiOHnXEap4TF09sJSc7H1sXbhtI=
+golang.org/x/oauth2 v0.21.0 h1:tsimM75w1tF/uws5rbeHzIWxEqElMehnc+iW793zsZs=
+golang.org/x/oauth2 v0.21.0/go.mod h1:XYTD2NtWslqkgxebSiOHnXEap4TF09sJSc7H1sXbhtI=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=