Update blinker requirement from <1.5,>=1.3 to >=1.3,<1.8 (#2519)

setup.py

@@ -27,7 +27,7 @@
     "pillow>=9.2,<9.3",
     "arrow>=0.4,<=0.13",
     "bcrypt>=3.1.1,<3.2",
-    "blinker>=1.3,<1.5",
+    "blinker>=1.3,<1.8",
     "celery[redis]>=5.2.7,<5.3",
     "cerberus>=1.3.2,<1.4",
     "redis>=4.5.2,<4.6",