build(deps): bump github.com/pion/rtp from 1.8.0 to 1.8.1 (#2129)

Bumps [github.com/pion/rtp](https://github.com/pion/rtp) from 1.8.0 to 1.8.1.
- [Release notes](https://github.com/pion/rtp/releases)
- [Changelog](https://github.com/pion/rtp/blob/master/.goreleaser.yml)
- [Commits](https://github.com/pion/rtp/compare/v1.8.0...v1.8.1)

---
updated-dependencies:
- dependency-name: github.com/pion/rtp
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

go.mod

@@ -20,7 +20,7 @@ require (
 	github.com/pion/ice/v2 v2.3.9
 	github.com/pion/interceptor v0.1.17
 	github.com/pion/rtcp v1.2.10
-	github.com/pion/rtp v1.8.0
+	github.com/pion/rtp v1.8.1
 	github.com/pion/sdp/v3 v3.0.6
 	github.com/pion/webrtc/v3 v3.2.13
 	github.com/stretchr/testify v1.8.4

go.sum

@@ -130,8 +130,9 @@ github.com/pion/randutil v0.1.0/go.mod h1:XcJrSMMbbMRhASFVOlj/5hQial/Y8oH/HVo7TB
 github.com/pion/rtcp v1.2.10 h1:nkr3uj+8Sp97zyItdN60tE/S6vk4al5CPRR6Gejsdjc=
 github.com/pion/rtcp v1.2.10/go.mod h1:ztfEwXZNLGyF1oQDttz/ZKIBaeeg/oWbRYqzBM9TL1I=
 github.com/pion/rtp v1.7.13/go.mod h1:bDb5n+BFZxXx0Ea7E5qe+klMuqiBrP+w8XSjiWtCUko=
-github.com/pion/rtp v1.8.0 h1:SYD7040IR+NqrGBOc2GDU5iDjAR+0m5rnX/EWCUMNhw=
 github.com/pion/rtp v1.8.0/go.mod h1:pBGHaFt/yW7bf1jjWAoUjpSNoDnw98KTMg+jWWvziqU=
+github.com/pion/rtp v1.8.1 h1:26OxTc6lKg/qLSGir5agLyj0QKaOv8OP5wps2SFnVNQ=
+github.com/pion/rtp v1.8.1/go.mod h1:pBGHaFt/yW7bf1jjWAoUjpSNoDnw98KTMg+jWWvziqU=
 github.com/pion/sctp v1.8.5/go.mod h1:SUFFfDpViyKejTAdwD1d/HQsCu+V/40cCs2nZIvC3s0=
 github.com/pion/sctp v1.8.7 h1:JnABvFakZueGAn4KU/4PSKg+GWbF6QWbKTWZOSGJjXw=
 github.com/pion/sctp v1.8.7/go.mod h1:g1Ul+ARqZq5JEmoFy87Q/4CePtKnTJ1QCL9dBBdN6AU=