chore(ci): fix regex for enabling development dependencies

Author: philprime

.github/workflows/build-test.yml

@@ -21,7 +21,7 @@ jobs:
           fetch-depth: 2
 
       - name: Enable development dependencies
-        run: sed -i.bak "s/\/\/dev//g" Package.swift
+        run: sed -i.bak "s/\/\/ dev//g" Package.swift
 
       - name: Build
         run: swift build