Add global label length limits #5

Job	Run time
Go tests	22m 57s
Go tests on Windows	11m 16s
Go tests with previous Go version	11m 39s
Compliance testing	7m 57s
Build Prometheus for common architectures (2)	11m 51s
Build Prometheus for common architectures (0)	11m 48s
golangci-lint	3m 11s
Build Prometheus for common architectures (1)	11m 28s
Mixins tests	3m 10s
codeql / Analyze (javascript)	1m 22s
Check generated parser	1m 16s
UI tests	2m 15s
fuzzing / Run Go Fuzz Tests (FuzzParseOpenMetric)	6m 35s
fuzzing / Run Go Fuzz Tests (FuzzParseMetricText)	6m 43s
More Go tests	8m 22s
fuzzing / Run Go Fuzz Tests (FuzzParseExpr)	6m 42s
fuzzing / Run Go Fuzz Tests (FuzzParseMetricSelector)	6m 45s
Build Prometheus for all architectures	0s
Report status of build Prometheus for all architectures	0s
fuzzing / Fuzzing	4s
Publish UI on npm Registry	1m 46s
Publish release artefacts	0s
Publish main branch artifacts	0s
	2h 17m 7s

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