chore(deps): widen utopia-php/cache constraint to ^3.1

3.1.* excluded the 3.2.0 release (purge-tombstone lease, backward-compatible and
opt-in). ^3.1 keeps the 3.1 floor the query/getDocument lease needs while
accepting compatible minors, matching the ^3.0 constraint the rest of the
ecosystem (server-ce, domains, vcs) already uses. Unblocks consumers that need
cache 3.2.0.

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

Author: abnegate

composer.json

@@ -40,7 +40,7 @@
         "ext-redis": "*",
         "utopia-php/validators": "0.2.*",
         "utopia-php/console": "0.1.*",
-        "utopia-php/cache": "3.1.*",
+        "utopia-php/cache": "^3.1.0",
         "utopia-php/pools": "1.*",
         "utopia-php/mongo": "1.*"
     },