Scraping: stop storing discovered labels #633

Job	Run time
Check generated parser	12s
Build Prometheus for all architectures	0s
Build Prometheus for common architectures (0)	6m 20s
fuzzing	0s
Build Prometheus for common architectures (1)	6m 9s
Go tests	16m 39s
Build Prometheus for common architectures (2)	6m 10s
golangci-lint	3m 2s
More Go tests	11m 57s
Go tests with previous Go version	7m 27s
Mixins tests	2m 14s
UI tests	4m 45s
Go tests on Windows	12m 55s
codeql / Analyze (javascript)	1m 51s
Publish UI on npm Registry	1m 30s
Publish release artefacts	0s
Publish main branch artifacts	0s
	1h 21m 11s

Provide feedback