tests: Upper bound on fakeredis on old Python versions (#4482)

Author: sentrivana

scripts/populate_tox/tox.jinja

@@ -295,7 +295,7 @@ deps =
     # Redis
     redis: fakeredis!=1.7.4
     redis: pytest<8.0.0
-    {py3.6,py3.7}-redis: fakeredis!=2.26.0  # https://github.com/cunla/fakeredis-py/issues/341
+    {py3.6,py3.7,py3.8}-redis: fakeredis<2.26.0
     {py3.7,py3.8,py3.9,py3.10,py3.11,py3.12,py3.13}-redis: pytest-asyncio
     redis-v3: redis~=3.0
     redis-v4: redis~=4.0

tox.ini

@@ -456,7 +456,7 @@ deps =
     # Redis
     redis: fakeredis!=1.7.4
     redis: pytest<8.0.0
-    {py3.6,py3.7}-redis: fakeredis!=2.26.0  # https://github.com/cunla/fakeredis-py/issues/341
+    {py3.6,py3.7,py3.8}-redis: fakeredis<2.26.0
     {py3.7,py3.8,py3.9,py3.10,py3.11,py3.12,py3.13}-redis: pytest-asyncio
     redis-v3: redis~=3.0
     redis-v4: redis~=4.0