Revert "bump euphonic requirement"

This reverts commit 75f77f1.

Let's see if the CI will pass before doing this version bump and
cleaning up; currently some code depends on private attributes that
have changed in Euphonic 1.4.

Author: ajjackson

conda/recipes/conda_build_config.yaml

@@ -143,7 +143,7 @@ libopenblas:
   - '!=0.3.23,!=0.3.24,!=0.3.25, !=0.3.28'
 
 euphonic:
-  - '>=1.4.0,<2.0'
+  - '>=1.2.1,<2.0'
 
 librdkafka:
   - '>=1.6.0'