Bump github.com/prometheus/common from 0.45.0 to 0.46.0

Bumps [github.com/prometheus/common](https://github.com/prometheus/common) from 0.45.0 to 0.46.0.
- [Release notes](https://github.com/prometheus/common/releases)
- [Commits](https://github.com/prometheus/common/compare/v0.45.0...v0.46.0)

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

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

vendor/github.com/prometheus/common/model/signature.go

@@ -22,10 +22,8 @@ import (
 // when calculating their combined hash value (aka signature aka fingerprint).
 const SeparatorByte byte = 255
 
-var (
-	// cache the signature of an empty label set.
-	emptyLabelSignature = hashNew()
-)
+// cache the signature of an empty label set.
+var emptyLabelSignature = hashNew()
 
 // LabelsToSignature returns a quasi-unique signature (i.e., fingerprint) for a
 // given label set. (Collisions are possible but unlikely if the number of label