fix(deps): require protobuf <4.0.0dev (#334)

Author: parthea

setup.py

@@ -50,7 +50,8 @@
         # Until this issue is closed
         # https://github.com/googleapis/google-cloud-python/issues/10566
         "google-api-core[grpc] >= 1.31.5, <3.0.0dev,!=2.0.*,!=2.1.*,!=2.2.*,!=2.3.0",
-        "proto-plus >= 1.15.0",
+        "proto-plus >= 1.15.0, <2.0.0dev",
+        "protobuf >= 3.19.0, <4.0.0dev",
     ),
     python_requires=">=3.6",
     classifiers=[

testing/constraints-3.6.txt

@@ -7,3 +7,4 @@
 # Then this file should have foo==1.14.0
 google-api-core==1.31.5
 proto-plus==1.15.0
+protobuf==3.19.0