ci: stop building PHP 7.4, 8.0 and 8.1 images

All four image matrices (cac, cac-fpm, cac-litespeed, cac-lsphp) and the
emergency lsphp-from-source workflow now build PHP 8.2-8.5 only. 7.4-8.1 are
end of life and got no upstream fix for CVE-2026-109618/109619; no fleet site
runs them any more. Existing :php74/:php80/:php81 tags stay in the registry
but are no longer rebuilt.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/lsphp-source-emergency.yaml

@@ -39,7 +39,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        phpver: [81, 82, 83, 84, 85]
+        phpver: [82, 83, 84, 85]
         image: [lsphp, litespeed]
     steps:
       - name: Select this job's target (skip if not requested)
@@ -57,7 +57,7 @@ jobs:
           case "$IN_PROD" in true|false) ;; *) echo "::error::push_production_tags must be true|false, got '$IN_PROD'"; exit 1 ;; esac
           v=""
           for pair in $IN_VERSIONS; do
-            [[ "$pair" =~ ^(8[1-5])=([0-9]+\.[0-9]+\.[0-9]+)$ ]] || { echo "::error::bad php_versions entry '$pair' (want NN=X.Y.Z, NN in 81..85)"; exit 1; }
+            [[ "$pair" =~ ^(8[2-5])=([0-9]+\.[0-9]+\.[0-9]+)$ ]] || { echo "::error::bad php_versions entry '$pair' (want NN=X.Y.Z, NN in 82..85)"; exit 1; }
             [ "${BASH_REMATCH[1]}" = "$PHPVER" ] && v="${BASH_REMATCH[2]}"
           done
           echo "prod=$IN_PROD" >> "$GITHUB_OUTPUT"