ref: remove PlanOut (#61056)

experiments framework based on PlanOut was removed in getsentry

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requirements-dev-frozen.txt

@@ -120,7 +120,6 @@ phabricator==0.7.0
 phonenumberslite==8.12.55
 pillow==9.3.0
 pip-tools==6.7.0
-planout==0.6.0
 platformdirs==2.5.2
 pluggy==0.13.1
 pre-commit==3.3.2

requirements-frozen.txt

@@ -84,7 +84,6 @@ petname==2.6
 phabricator==0.7.0
 phonenumberslite==8.12.55
 pillow==9.3.0
-planout==0.6.0
 progressbar2==3.41.0
 prompt-toolkit==3.0.41
 proto-plus==1.22.2

requirements-getsentry.txt

@@ -7,7 +7,6 @@
 # requirements synchronization across the two repositories
 
 Avalara==20.9.0
-PlanOut==0.6.0
 pycountry==17.5.14
 pyvat==1.3.15
 reportlab==4.0.7