Fix type annotation so it's ok in newest sphinx/autoapi

jepler · jepler · commit f45c0d2dde98 · 2025-02-07T20:59:50.000-06:00
this otherwise gets
```
astroid.exceptions.InferenceError: Inference failed for all members of [&lt;BinOp l.13 at 0x7fd379c99e80&gt;].
```
diff --git a/shared-bindings/synthio/__init__.c b/shared-bindings/synthio/__init__.c
@@ -34,7 +34,7 @@
 //|
 //|
 
-//| AnyBiquad = Biquad | BlockBiquad
+//| AnyBiquad = "Biquad | BlockBiquad"
 //|
 //| class EnvelopeState:
 //|     ATTACK: EnvelopeState
