build: bump ilt-panphon to 0.21.4 which removes setuptools dep

Author: joanise

pyproject.toml

@@ -74,7 +74,7 @@ heroku = [
     "readalongs[api]",
     # We don't actually use the panphon 0.22 improvements on heroku so stick to
     # 0.21 with its lighter weight dependencies
-    "panphon<0.22",
+    "ilt-panphon>=0.21.4,<0.22",
 ]
 
 ci = [

requirements.txt

@@ -16,7 +16,7 @@
 # - soundswallower~=0.6.0
 # - webvtt-py==0.5.1
 # - gunicorn>=23.0.0; platform_system != "Windows"
-# - panphon<0.22
+# - ilt-panphon<0.22,>=0.21.4
 # - uvicorn>=0.30.1
 #
 
@@ -75,7 +75,7 @@ openpyxl==3.1.5
     # via g2p
 packaging==25.0
     # via gunicorn
-ilt-panphon==0.21.3
+ilt-panphon==0.21.4
     # via
     #   hatch.envs.prod
     #   g2p
@@ -129,6 +129,3 @@ uvicorn==0.38.0
     # via hatch.envs.prod
 webvtt-py==0.5.1
     # via hatch.envs.prod
-
-# The following packages are considered to be unsafe in a requirements file:
-# setuptools