.github/workflows/build_wheels.yml: default flavours=false.

I.e. build single pymudf wheel, without separate pymupdfb wheel.

Author: julian-smith-artifex-com

.github/workflows/build_wheels.yml

@@ -7,7 +7,7 @@ on:
       flavours:
         description: 'If set, we build separate PyMuPDF and PyMuPDFb wheels.'
         type: boolean
-        default: true
+        default: false
 
       sdist:
         type: boolean