build(deps): Bump github.com/creachadair/taskgroup from 0.3.2 to 0.8.1

Bumps [github.com/creachadair/taskgroup](https://github.com/creachadair/taskgroup) from 0.3.2 to 0.8.1.
- [Commits](creachadair/taskgroup@v0.3.2...v0.8.1)

---
updated-dependencies:
- dependency-name: github.com/creachadair/taskgroup
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/adlio/schema v1.3.0
 	github.com/btcsuite/btcd v0.22.0-beta
 	github.com/btcsuite/btcutil v1.0.3-0.20201208143702-a53e38424cce
-	github.com/creachadair/taskgroup v0.3.2
+	github.com/creachadair/taskgroup v0.8.1
 	github.com/facebookgo/ensure v0.0.0-20160127193407-b4ab57deab51 // indirect
 	github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 // indirect
 	github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 // indirect

go.sum

@@ -223,8 +223,8 @@ github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwc
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.1/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/creachadair/taskgroup v0.3.2 h1:zlfutDS+5XG40AOxcHDSThxKzns8Tnr9jnr6VqkYlkM=
-github.com/creachadair/taskgroup v0.3.2/go.mod h1:wieWwecHVzsidg2CsUnFinW1faVN4+kq+TDlRJQ0Wbk=
+github.com/creachadair/taskgroup v0.8.1 h1:+wKambTTYyF6KCJ8P8IWrCr7GQq9SnJ/JXzgORN4ZU4=
+github.com/creachadair/taskgroup v0.8.1/go.mod h1:+1hJc8zL1rQkxcMVqEYJ0UPGtwl6Iz1+fd4zcOLtt+A=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/cyphar/filepath-securejoin v0.2.2/go.mod h1:FpkQEhXnPnOthhzymB7CGsFk2G9VLXONKD9G7QGMM+4=