⬇️ e2e mock: keep Go floor at 1.22 (yaegi ceiling)

Revert the mock module back to go 1.22 and make the e2e workflow read the Go
version from go.mod (go-version-file) instead of hardcoding 1.23.

Rationale: the plugin is interpreted by yaegi, and even Traefik v3.7.1 ships
yaegi v0.16.1 (Go 1.22), so the project stays on 1.22. The earlier bump to 1.23
is dropped (plugin go.mod stays 1.22, see #330 for the Renovate cap + CI pin).
Mock + all six scenarios verified on Go 1.22.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/e2e.yml

@@ -21,7 +21,9 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: "1.23"
+          # Track go.mod (Go 1.22) — the plugin's yaegi-bound floor. Keeps the
+          # single source of truth and builds the mock on the supported version.
+          go-version-file: go.mod
       # CI runs the binary/mock suite only: Traefik as a downloaded binary +
       # a small LAPI mock (no Docker, no real Crowdsec). It validates the
       # plugin's own behaviour. Crowdsec / AppSec correctness is upstream's

tests/e2e/mock/mocklapi/go.mod

@@ -3,4 +3,4 @@
 // golangci-lint and `go mod vendor`. Stdlib only — no dependencies.
 module mocklapi
 
-go 1.23
+go 1.22