Pin transient dependency pyrsistent to < 0.17.0

[ChristineTChen]

What does this PR do?

Add flag to pip install to resolve dependencies

Motivation

https://github.com/tobgu/pyrsistent/blob/97190f8ad43553603a95a83361d4c0fe02e86970/CHANGES.txt#L4-L5

Dropped py2 support resulting in CI failing https://dev.azure.com/datadoghq/integrations-core/_build/results?buildId=23293&view=logs&j=910f82a4-622d-5ace-f877-8b75c045486c&t=b8a76c45-01d6-50b1-e11b-d9fedb0dbe38&l=230

Additional Notes

Use #7545 when issue is resolved via tobgu/pyrsistent#206

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[codecov]

Codecov Report

Merging #7546 into master will decrease coverage by 9.96%.
The diff coverage is n/a.

Impacted Files	Coverage Δ
datadog_checks_dev/tests/test_docker.py	48.14% <0.00%> (-51.86%)	⬇️
datadog_checks_dev/tests/tooling/test_utils.py	73.40% <0.00%> (-26.60%)	⬇️
datadog_checks_dev/datadog_checks/dev/env.py	22.72% <0.00%> (-20.46%)	⬇️
datadog_checks_dev/datadog_checks/dev/warn.py	63.63% <0.00%> (-18.19%)	⬇️
datadog_checks_dev/tests/test_conditions.py	82.25% <0.00%> (-17.75%)	⬇️
datadog_checks_dev/datadog_checks/dev/docker.py	24.81% <0.00%> (-17.30%)	⬇️
...atadog_checks_dev/datadog_checks/dev/structures.py	68.85% <0.00%> (-13.12%)	⬇️
datadog_checks_dev/datadog_checks/dev/_env.py	53.24% <0.00%> (-9.10%)	⬇️
...atadog_checks_dev/datadog_checks/dev/subprocess.py	72.97% <0.00%> (-5.41%)	⬇️
...atadog_checks_dev/datadog_checks/dev/conditions.py	81.13% <0.00%> (-4.72%)	⬇️
... and 832 more