Update module github.com/prometheus/client_golang to v1.21.1

go.mod

go.sum

vendor/github.com/klauspost/compress/.goreleaser.yml

vendor/github.com/klauspost/compress/README.md

vendor/github.com/klauspost/compress/fse/decompress.go

vendor/github.com/klauspost/compress/huff0/decompress.go

vendor/github.com/klauspost/compress/zstd/blockdec.go

vendor/github.com/klauspost/compress/zstd/enc_better.go

vendor/github.com/klauspost/compress/zstd/enc_dfast.go

vendor/github.com/klauspost/compress/zstd/encoder.go

vendor/github.com/klauspost/compress/zstd/framedec.go

vendor/github.com/klauspost/compress/zstd/seqdec_amd64.go

vendor/github.com/klauspost/compress/zstd/seqdec_amd64.s

vendor/github.com/klauspost/compress/zstd/zstd.go

...or/github.com/prometheus/client_golang/prometheus/desc.go

...rometheus/client_golang/prometheus/go_collector_latest.go

...thub.com/prometheus/client_golang/prometheus/histogram.go

...m/prometheus/client_golang/prometheus/internal/difflib.go

...s/client_golang/prometheus/internal/go_runtime_metrics.go

.../github.com/prometheus/client_golang/prometheus/metric.go