SNOW-1877354: Add pyproject.toml and tox dev dependency (#2843)

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1. Which Jira issue is this PR addressing? Make sure that there is an
accompanying issue to your PR.

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   Fixes SNOW-1877354

2. Fill out the following pre-review checklist:

- [ ] I am adding a new automated test(s) to verify correctness of my
new code
- [ ] If this test skips Local Testing mode, I'm requesting review from
@snowflakedb/local-testing
   - [ ] I am adding new logging messages
   - [ ] I am adding a new telemetry message
   - [ ] I am adding new credentials
   - [ ] I am adding a new dependency
- [ ] If this is a new feature/behavior, I'm adding the Local Testing
parity changes.
- [x] I acknowledge that I have ensured my changes to be thread-safe.
Follow the link for more information: [Thread-safe Developer
Guidelines](https://github.com/snowflakedb/snowpark-python/blob/main/CONTRIBUTING.md#thread-safe-development)

3. Please describe how your code solves the related issue.

As described in the linked JIRA, the `protoc-wheel-0` and
`mypy-protobuf` dev dependencies must be installed _before_ `setup.py`
is run, so a clean `pip install snowflake-snowpark-python[development]`
will error if these packages were not installed beforehand. By adding
`pyproject.toml` according to [these
instructions](https://packaging.python.org/en/latest/guides/modernize-setup-py-project/#how-to-handle-additional-build-time-dependencies),
we're able to specify these dependencies before `setup.py` is invoked,
thereby removing the need to explicitly `pip install` those packages
first. This can be verified by attempting to install the repository from
a new conda environment, which fails on current main without first
installing `protoc-wheel-0` and `mypy-protobuf`.

This PR also incidentally adds `tox` as a dev dependency, as we use it
frequently for testing environments.

pyproject.toml

@@ -0,0 +1,7 @@
+[build-system]
+requires = [
+    "setuptools",
+    "protoc-wheel-0==21.1", # Protocol buffer compiler for Snowpark IR
+    "mypy-protobuf", # used in generating typed Python code from protobuf for Snowpark IR
+]
+build-backend = "setuptools.build_meta"

setup.py

@@ -58,9 +58,8 @@
     "graphviz",  # used in plot tests
     "pytest-assume",  # sql counter check
     "decorator",  # sql counter check
-    "protoc-wheel-0==21.1",  # Protocol buffer compiler, for Snowpark IR
-    "mypy-protobuf",  # used in generating typed Python code from protobuf for Snowpark IR
     "lxml",  # used in read_xml tests
+    "tox",  # used for setting up testing environments
 ]
 
 # read the version