Remove the CrowdSec decision feed (closes #315)

sneak ruled to remove it. Gone: the heuristic crowdsec, the ban cause
crowdsec and its earlier_bans count, the tag crowdsec, the settings
SWW_WAF_CROWDSEC_LAPI_URL and SWW_WAF_CROWDSEC_LAPI_KEY, the decision
list fetch and parse in internal/reputation, their tests, and every
mention in the README, SPEC.md and docs/. EVALUATION.md keeps its
comparison of tools.

The ban ledger's internal ban function loses its expires parameter,
which only CrowdSec bans used.

Model: opus-5-5
Co-authored-by: clawbot <sneak+clawbot@sneak.cloud>

internal/waf/heuristics.go

@@ -60,7 +60,6 @@ func afterLookup() []heuristic {
 	return []heuristic{
 		countries{},
 		blocklists{},
-		crowdSec{},
 		dnsbl{},
 		abuseIPDB{},
 		tagDeny{},