Bump go version to 1.21 (#215) #31

Benchdiff Results

Benchmark Command: go test ./... -run ^ -bench . -count 5 -benchtime 100ms -cpu 1,2 -benchmem

HEAD sha: 8b51b7a

Base sha: 8b51b7a

Degraded: false

pkg: github.com/elastic/apm-data/codec
goos: linux
goarch: amd64

name	old time/op (ns/op)	±	new time/op (ns/op)	±	delta	±
Encode/format=json	33044.6	59%	39851.8	55%	~	(p=0.690 n=5+5)
Encode/format=json-2	14914	10%	14156.4	1%	~	(p=0.690 n=5+5)
Encode/format=vtproto	6383.2	1%	6431.2	1%	~	(p=0.548 n=5+5)
Encode/format=vtproto-2	3482.8	2%	3498.6	1%	~	(p=0.421 n=5+5)
Decode/format=json	127389	2%	129818	1%	~	(p=0.056 n=5+5)
Decode/format=json-2	65789.4	5%	65095.2	4%	~	(p=0.841 n=5+5)
Decode/format=vtproto	22555.4	1%	22244.4	2%	-1.38%	(p=0.032 n=5+5)
Decode/format=vtproto-2	13217.6	2%	13345.2	5%	~	(p=0.841 n=5+5)

name	old bytes/op (bytes/op)	±	new bytes/op (bytes/op)	±	delta	±
Encode/format=json	6564	0%	6564	0%	~	(all equal)
Encode/format=json-2	6564	0%	6564	0%	~	(all equal)
Encode/format=vtproto	2775	0%	2775	0%	~	(all equal)
Encode/format=vtproto-2	2775	0%	2775	0%	~	(all equal)

name	old alloc/op (B/op)	±	new alloc/op (B/op)	±	delta	±
Encode/format=json	7752	0%	7752	0%	~	(all equal)
Encode/format=json-2	7753	0%	7753	0%	~	(all equal)
Encode/format=vtproto	3200	0%	3200	0%	~	(all equal)
Encode/format=vtproto-2	3200	0%	3200	0%	~	(all equal)
Decode/format=json	14488	0%	14488	0%	~	(all equal)
Decode/format=json-2	14488	0%	14488	0%	~	(all equal)
Decode/format=vtproto	12962	0%	12961.6	0%	~	(p=0.643 n=5+5)
Decode/format=vtproto-2	13001	0%	13001.6	0%	~	(p=1.000 n=5+5)

name	old allocs/op (allocs/op)	±	new allocs/op (allocs/op)	±	delta	±
Encode/format=json	30	0%	30	0%	~	(all equal)
Encode/format=json-2	30	0%	30	0%	~	(all equal)
Encode/format=vtproto	5	0%	5	0%	~	(all equal)
Encode/format=vtproto-2	5	0%	5	0%	~	(all equal)
Decode/format=json	397	0%	397	0%	~	(all equal)
Decode/format=json-2	397	0%	397	0%	~	(all equal)
Decode/format=vtproto	348	0%	348	0%	~	(all equal)
Decode/format=vtproto-2	348	0%	348	0%	~	(all equal)

pkg: github.com/elastic/apm-data/input/elasticapm/internal/decoder
goos: linux
goarch: amd64

name	old time/op (ns/op)	±	new time/op (ns/op)	±	delta	±
NDStreamDecoder	305.4	15%	290.02	5%	~	(p=0.548 n=5+5)
NDStreamDecoder-2	159.7	1%	157.1	2%	~	(p=0.175 n=5+5)

name	old alloc/op (B/op)	±	new alloc/op (B/op)	±	delta	±
NDStreamDecoder	72	0%	72	0%	~	(all equal)
NDStreamDecoder-2	72	0%	72	0%	~	(all equal)

name	old allocs/op (allocs/op)	±	new allocs/op (allocs/op)	±	delta	±
NDStreamDecoder	4	0%	4	0%	~	(all equal)
NDStreamDecoder-2	4	0%	4	0%	~	(all equal)

pkg: github.com/elastic/apm-data/model/modeljson
goos: linux
goarch: amd64

name	old time/op (ns/op)	±	new time/op (ns/op)	±	delta	±
APMEventToJSON/to-json	15449.8	6%	15470.6	8%	~	(p=0.841 n=5+5)
APMEventToJSON/to-json-2	12581.8	2%	13452.2	2%	+6.92%	(p=0.008 n=5+5)

name	old alloc/op (B/op)	±	new alloc/op (B/op)	±	delta	±
APMEventToJSON/to-json	2472	0%	2472	0%	~	(all equal)
APMEventToJSON/to-json-2	2472	0%	2472	0%	~	(all equal)

name	old allocs/op (allocs/op)	±	new allocs/op (allocs/op)	±	delta	±
APMEventToJSON/to-json	37	0%	37	0%	~	(all equal)
APMEventToJSON/to-json-2	37	0%	37	0%	~	(all equal)