build(deps): bump github.com/slack-go/slack from 0.11.3 to 0.12.1

Bumps [github.com/slack-go/slack](https://github.com/slack-go/slack) from 0.11.3 to 0.12.1.
- [Release notes](https://github.com/slack-go/slack/releases)
- [Changelog](https://github.com/slack-go/slack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/slack-go/slack/compare/v0.11.3...v0.12.1)

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

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

go.mod

@@ -28,7 +28,7 @@ require (
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
 	github.com/olebedev/when v0.0.0-20190311101825-c3b538a97254
 	github.com/rs/zerolog v1.28.0
-	github.com/slack-go/slack v0.11.3
+	github.com/slack-go/slack v0.12.1
 	github.com/stretchr/testify v1.8.0
 	github.com/trubitsyn/go-zero-width v1.0.1
 	github.com/velour/velour v0.0.0-20160303155839-8e090e68d158

go.sum

@@ -158,8 +158,8 @@ github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQD
 github.com/saintfish/chardet v0.0.0-20120816061221-3af4cd4741ca h1:NugYot0LIVPxTvN8n+Kvkn6TrbMyxQiuvKdEwFdR9vI=
 github.com/saintfish/chardet v0.0.0-20120816061221-3af4cd4741ca/go.mod h1:uugorj2VCxiV1x+LzaIdVa9b4S4qGAcH6cbhh4qVxOU=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
-github.com/slack-go/slack v0.11.3 h1:GN7revxEMax4amCc3El9a+9SGnjmBvSUobs0QnO6ZO8=
-github.com/slack-go/slack v0.11.3/go.mod h1:hlGi5oXA+Gt+yWTPP0plCdRKmjsDxecdHxYQdlMQKOw=
+github.com/slack-go/slack v0.12.1 h1:X97b9g2hnITDtNsNe5GkGx6O2/Sz/uC20ejRZN6QxOw=
+github.com/slack-go/slack v0.12.1/go.mod h1:hlGi5oXA+Gt+yWTPP0plCdRKmjsDxecdHxYQdlMQKOw=
 github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
 github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=