allow protobuf < 5.0.0

fixes #206

Author: Aaron Gabriel Neyer

setup.py

@@ -47,8 +47,8 @@
     include_package_data=True,
     install_requires=(
         "google-api-core[grpc] >= 1.32.0, <3.0.0dev,!=2.0.*,!=2.1.*,!=2.2.*,!=2.3.*,!=2.4.*,!=2.5.*,!=2.6.*,!=2.7.*",
-        "proto-plus >= 1.15.0, <2.0.0dev",
-        "protobuf >= 3.19.0, <4.0.0dev",
+        "proto-plus >= 1.22.0, <2.0.0dev",
+        "protobuf >= 3.19.0, <5.0.0dev",
         "grpc-google-iam-v1 >= 0.12.4, <1.0.0dev",
     ),
     python_requires=">=3.7",