remove remote config from shared rules file

Remote convention is local to the contributor, not a project rule.

Author: cderv

.claude/rules/quarto-web-workflow.md

@@ -8,6 +8,3 @@
 
 Always PR to `main` first for shared content. Never PR directly to `prerelease` for changes that apply to both stable and prerelease.
 
-## Remotes
-
-Push PR branches to `upstream` (quarto-dev/quarto-web), not `origin`.