Bump setuptools from 67.8.0 to 68.0.0 in /requirements (#1467)

* Bump setuptools from 67.8.0 to 68.0.0 in /requirements

Bumps [setuptools](https://github.com/pypa/setuptools) from 67.8.0 to 68.0.0.
- [Release notes](https://github.com/pypa/setuptools/releases)
- [Changelog](https://github.com/pypa/setuptools/blob/main/NEWS.rst)
- [Commits](pypa/setuptools@v67.8.0...v68.0.0)

---
updated-dependencies:
- dependency-name: setuptools
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* Add changelog entry

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ed Morley <501702+edmorley@users.noreply.github.com>

GUS-W-13659044.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Updated pip from 23.1.2 to 23.2. ([#1465](https://github.com/heroku/heroku-buildpack-python/pull/1465))
+- Updated setuptools from 67.8.0 to 68.0.0. ([#1467](https://github.com/heroku/heroku-buildpack-python/pull/1467))
 - Update the Python 3.7 deprecation message to reflect that it has now reached end-of-life. ([#1460](https://github.com/heroku/heroku-buildpack-python/pull/1460))
 
 ## v233 (2023-06-07)

requirements/setuptools.txt

@@ -1 +1 @@
-setuptools==67.8.0
+setuptools==68.0.0