fix: pin requests <2.32 until docker/docker-py#3256 is resolved

Author: jrmfg

tox.ini

@@ -9,6 +9,7 @@ deps =
     pytest-cov
     pytest-integration
     pretend
+    requests<2.32
 setenv =
     PYTESTARGS = --cov=functions_framework --cov-branch --cov-report term-missing --cov-fail-under=100
     windows-latest: PYTESTARGS =