Update psutil requirement from <5.9.7 to <5.9.8

Updates the requirements on [psutil](https://github.com/giampaolo/psutil) to permit the latest version.
- [Changelog](https://github.com/giampaolo/psutil/blob/master/HISTORY.rst)
- [Commits](giampaolo/psutil@release-0.1.0...release-5.9.7)

---
updated-dependencies:
- dependency-name: psutil
  dependency-type: direct:development
...

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

dev/requirements-dev.txt

@@ -1,6 +1,6 @@
 cython>=0.29.22
 gevent
-psutil<5.9.7
+psutil<5.9.8
 pytest
 pytest-subtests
 pytest-timeout

setup.py

@@ -330,7 +330,7 @@ def mk_long_description(numrev=1):
     ],
     zip_safe = False,
     setup_requires=['setuptools_scm[toml]>=5.0,<9.0', 'Cython>=0.29.22'],
-    tests_require=['psutil<5.9.7', 'pytest', 'pytest-timeout'],
+    tests_require=['psutil<5.9.8', 'pytest', 'pytest-timeout'],
     ext_modules = ext_modules(),
     packages = [ 'pymssql'],
     package_dir = {'': 'src'},