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

docs/request-log.md

@@ -97,7 +97,7 @@ Every one of these lines has:
     - `client_denied`: refused for `SWW_WAF_DENY_NETS`, for a reputation source
       with the action `deny`, or for a tag in `SWW_WAF_TAG_DENY`;
     - `temporarily_banned`: refused under a ban that runs out, or for a `ban`
-      rule, a trap path or a CrowdSec decision that made such a ban;
+      rule or a trap path that made such a ban;
     - `permanently_banned`: refused under a ban that never runs out, including a
       ban this request made or made permanent;
     - `country_denied`, `client_is_rate_limited`, `blocked_by_block_rule` and
@@ -118,8 +118,6 @@ Every one of these lines has:
     - `countries`: `country`, and `setting`, the country list that refused it;
     - `tag_deny`: `tag`, the tag of `SWW_WAF_TAG_DENY` the request carries;
     - `blocklists`: `lists`, the blocklist URLs that list the client;
-    - `crowdsec`: `scenario`, the decision's scenario, and `expires`, when the
-      decision ends;
     - `dnsbl`: `zones`, the DNS blocklist zones that list the client, their keys
       masked;
     - `abuseipdb`: `score`, and `min_score`, `SWW_WAF_ABUSEIPDB_MIN_SCORE`;
@@ -171,7 +169,6 @@ Every one of these lines has:
   and the rules that matched, for a request it inspected.
 - `reputation`: the sources the client is on, in this order:
     - blocklist URLs;
-    - the CrowdSec decision list's URL;
     - DNS blocklist zones;
     - `abuseipdb`.
 - `tags`: the request's tags, sorted, left out when it has none. Each tag and