chore(deps-dev): keep Python 3.9 on sanic 25.x

sanic 25.12 requires Python >=3.10, so the naive bump stranded 3.9
(nothing installable). Split the requirement so 3.9 stays on the
25.3.0-25.9.0 line and 3.10+ takes 25.12.1.

Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>

Author: WilliamBergamin

requirements/adapter_dev.txt

@@ -56,9 +56,11 @@ setuptools<82
 # sanic
 # Note: Sanic pulls in tracerite via a wildcard version, so tracerite is co-pinned here.
 # Note: tracerite > 1.1.2 is incompatible with Python <= 3.8 and ships no requires_python, so an explicit ceiling is required.
+# Note: sanic 25.12 requires Python >=3.10; 3.9 stays on the older 25.x line.
 tracerite<1.1.2; python_version < "3.9"
 sanic>=21,<24; python_version < "3.9"
-sanic>=25.12.1,<26; python_version >= "3.9"
+sanic>=25.3.0,<25.12.0; python_version >= "3.9" and python_version < "3.10"
+sanic>=25.12.1,<26; python_version >= "3.10"
 
 # starlette
 # Note: starlette 0.49.3 requires Python >=3.9; 3.7/3.8 stay on the older pinned release.