build: use ~=0.2.2 instead of >=0.2.2

requirements.txt

@@ -8,7 +8,7 @@ g2p>=0.5.20210825
 lxml==4.6.5
 networkx==2.5
 numpy>=1.16.4
-soundswallower>=0.2.2
+soundswallower~=0.2.2
 pydub==0.23.1
 pympi-ling==1.69
 python-slugify==5.0.0