deps: remove upper bound on packaging dependency (#1440)

* deps: remove upper bound on packaging dependency

Towards #1435

* install prerelease version of packaging

* bump minimum packaging version

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

noxfile.py

@@ -300,6 +300,11 @@ def prerelease_deps(session):
         "--upgrade",
         "pandas",
     )
+    session.install(
+        "--pre",
+        "--upgrade",
+        "git+https://github.com/pypa/packaging.git",
+    )
 
     session.install(
         "--pre",

setup.py

@@ -41,7 +41,7 @@
     # https://github.com/googleapis/google-cloud-python/issues/10566
     "google-cloud-core >= 1.4.1, <3.0.0dev",
     "google-resumable-media >= 0.6.0, < 3.0dev",
-    "packaging >= 14.3, <22.0.0dev",
+    "packaging >= 20.0.0",
     "protobuf>=3.19.5,<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",  # For the legacy proto-based types.
     "python-dateutil >= 2.7.2, <3.0dev",
     "requests >= 2.21.0, < 3.0.0dev",

testing/constraints-3.7.txt

@@ -17,6 +17,7 @@ ipython==7.0.1
 opentelemetry-api==1.1.0
 opentelemetry-instrumentation==0.20b0
 opentelemetry-sdk==1.1.0
+packaging==20.0.0
 pandas==1.1.0
 proto-plus==1.22.0
 protobuf==3.19.5