Minor spelling fix

Author: lwasser

.github/workflows/build-book.yml

@@ -1,7 +1,7 @@
 name: build-test-deploy-book
 
 # Only build PRs, the main branch, and releases. Pushes to branches will only
-# be built when a PR is opened. This avoids duplicated buids in PRs coming
+# be built when a PR is opened. This avoids duplicated builds in PRs coming
 # from branches in the origin repository (1 for PR and 1 for push).
 # This came from Leo's work with fatiando
 on: