build(deps): Bump github.com/prometheus/client_golang

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.8.0 to 1.10.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/master/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.8.0...v1.10.0)

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

go.mod

@@ -22,7 +22,7 @@ require (
 	github.com/oasisprotocol/ed25519 v0.0.0-20210127160119-f7017427c1ea
 	github.com/oasisprotocol/safeopen v0.0.0-20200528085122-e01cfdfc7661
 	github.com/pkg/errors v0.9.1
-	github.com/prometheus/client_golang v1.8.0
+	github.com/prometheus/client_golang v1.10.0
 	github.com/rcrowley/go-metrics v0.0.0-20200313005456-10cdbea86bc0
 	github.com/rs/cors v1.7.0
 	github.com/sasha-s/go-deadlock v0.2.0