Bump pytest-html from 2.1.1 to 3.1.1 in /perf-tests

Bumps [pytest-html](https://github.com/pytest-dev/pytest-html) from 2.1.1 to 3.1.1.
- [Release notes](https://github.com/pytest-dev/pytest-html/releases)
- [Changelog](https://github.com/pytest-dev/pytest-html/blob/master/docs/changelog.rst)
- [Commits](pytest-dev/pytest-html@v2.1.1...v3.1.1)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

perf-tests/requirements.txt

@@ -6,6 +6,6 @@ ipaddress==1.0.23 # >= 1.0.17
 cffi==1.14.5
 certifi==2020.12.5
 urllib3==1.26.3
-pytest-html==2.1.1
+pytest-html==3.1.1
 pytest-repeat==0.9.1
 locust==1.4.3