fix: Release requirements fix (#421)

* chore: Drop py36 from changelog

* fix: tox dependency < 4.0

* fix: adds api_compatibility_tests for 4.2.0

* fix: add the missing release_requirements.txt

* fix: add deps from other commands

* fix: skip_install false for test_release

* Update tox.ini

PR comments

Co-authored-by: Ritvik Kapila <61410899+RitvikKapila@users.noreply.github.com>

* fix: skip_install false for release

---------

Co-authored-by: Shubham Chaturvedi <scchatur@amazon.com>
Co-authored-by: Ritvik Kapila <61410899+RitvikKapila@users.noreply.github.com>

tox.ini

@@ -354,7 +354,8 @@ commands =
 
 [testenv:release]
 basepython = python3
-skip_install = true
+# Set skip_install false because we need to install the aws-encryption-sdk-cli for sphinx.
+skip_install = false
 deps = {[testenv:release-base]deps}
 passenv =
     {[testenv:release-base]passenv}