Update dependencies and cleanup

requirements/stable-psa.txt

@@ -1,3 +1,3 @@
 # Stable Python Social Auth, found in Open edX Olive
-social-auth-app-django==5.0.0
-social-auth-core==4.3.0
+social-auth-app-django>=5.0.0
+social-auth-core>=4.3.0

requirements/test.txt

@@ -1,5 +1,5 @@
 # Packages for testing
-pytest==7.1.1
-httpretty==1.1.4
-pycodestyle==2.8.0
+pytest>=7.1.1
+httpretty>=1.1.4
+pycodestyle>=2.8.0
 -e .