chore(spanner): Issue#1143 - Update dependency - Move grpc-interceptor to extras_required named testing

Author: bhatt4982

setup.py

@@ -43,7 +43,6 @@
     "sqlparse >= 0.4.4",
     "proto-plus >= 1.22.2, <2.0.0dev; python_version>='3.11'",
     "protobuf>=3.20.2,<5.0.0dev,!=3.20.0,!=3.20.1,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",
-    "grpc-interceptor >= 0.15.4",
 ]
 extras = {
     "tracing": [
@@ -52,6 +51,7 @@
         "opentelemetry-instrumentation >= 0.20b0, < 0.23dev",
     ],
     "libcst": "libcst >= 0.2.5",
+    "testing": "grpc-interceptor >= 0.15.4",
 }
 
 url = "https://github.com/googleapis/python-spanner"
@@ -99,4 +99,4 @@
     python_requires=">=3.7",
     include_package_data=True,
     zip_safe=False,
-)
+)