chore(pyroscope.write): Refactor ingest label parsing

This refactors the label parsing, so we reuse the upstream code, which
is part of the pyroscope/api module, since
grafana/pyroscope#3848.

go.mod

@@ -68,7 +68,7 @@ require (
 	github.com/grafana/loki/pkg/push v0.0.0-20240617182007-6c33561108ad // k206 branch
 	github.com/grafana/loki/v3 v3.0.0-20240617182007-6c33561108ad // k206 branch
 	github.com/grafana/pyroscope-go/godeltaprof v0.1.8
-	github.com/grafana/pyroscope/api v0.4.0
+	github.com/grafana/pyroscope/api v1.2.0
 	github.com/grafana/pyroscope/ebpf v0.4.8
 	github.com/grafana/regexp v0.0.0-20240518133315-a468a5bfb3bc
 	github.com/grafana/tail v0.0.0-20230510142333-77b18831edf0

go.sum

@@ -1898,8 +1898,8 @@ github.com/grafana/prometheus v1.8.2-0.20240514135907-13889ba362e6 h1:kih3d3M3dx
 github.com/grafana/prometheus v1.8.2-0.20240514135907-13889ba362e6/go.mod h1:yv4MwOn3yHMQ6MZGHPg/U7Fcyqf+rxqiZfSur6myVtc=
 github.com/grafana/pyroscope-go/godeltaprof v0.1.8 h1:iwOtYXeeVSAeYefJNaxDytgjKtUuKQbJqgAIjlnicKg=
 github.com/grafana/pyroscope-go/godeltaprof v0.1.8/go.mod h1:2+l7K7twW49Ct4wFluZD3tZ6e0SjanjcUUBPVD/UuGU=
-github.com/grafana/pyroscope/api v0.4.0 h1:J86DxoNeLOvtJhB1Cn65JMZkXe682D+RqeoIUiYc/eo=
-github.com/grafana/pyroscope/api v0.4.0/go.mod h1:MFnZNeUM4RDsDOnbgKW3GWoLSBpLzMMT9nkvhHHo81o=
+github.com/grafana/pyroscope/api v1.2.0 h1:SfHDZcEZ4Vbj/Jj3bTOSpm4IDB33wLA2xBYxROhiL4U=
+github.com/grafana/pyroscope/api v1.2.0/go.mod h1:CCWrMnwvTB5O+VBZfT+jO2RAvgm0GxdG2//kAWuMDhA=
 github.com/grafana/pyroscope/ebpf v0.4.8 h1:TVROQy1LPA33Fbi50hmWDOx/y83FK+7T3VmCDjfzGBk=
 github.com/grafana/pyroscope/ebpf v0.4.8/go.mod h1:lHQXQNVjREWGjMRer34NtuG4g5pVd6uwKCuebAx+OSc=
 github.com/grafana/regexp v0.0.0-20240518133315-a468a5bfb3bc h1:GN2Lv3MGO7AS6PrRoT6yV5+wkrOpcszoIsO4+4ds248=