build(deps): bump golang.org/x/tools from 0.20.0 to 0.21.0 in /tools

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

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

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

tools/go.mod

@@ -4,7 +4,7 @@ go 1.18
 
 require (
 	golang.org/x/lint v0.0.0-20210508222113-6edffad5e616
-	golang.org/x/tools v0.20.0
+	golang.org/x/tools v0.21.0
 )
 
 require golang.org/x/mod v0.17.0 // indirect

tools/go.sum

@@ -13,6 +13,6 @@ golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
-golang.org/x/tools v0.20.0 h1:hz/CVckiOxybQvFw6h7b/q80NTr9IUQb4s1IIzW7KNY=
-golang.org/x/tools v0.20.0/go.mod h1:WvitBU7JJf6A4jOdg4S1tviW9bhUxkgeCui/0JHctQg=
+golang.org/x/tools v0.21.0 h1:qc0xYgIbsSDt9EyWz05J5wfa7LOVW0YTLOXrqdLAWIw=
+golang.org/x/tools v0.21.0/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=