mesh-bootstrap: drop an unread parameter

A parameter nothing reads is a claim the function makes about what it needs, and
this one was wrong.

Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF

internal/bootstrap/apply.go

@@ -33,7 +33,7 @@ type Runner = apply.Runner
 // clearing the launcher's start counter. Those are facts about a running `mesh-host`, and this is
 // not one.
 func ApplyBundle(ctx context.Context, o Options, sys system.System, d *declaration.Declaration,
-	source string, run Runner, say func(string)) (apply.Report, error) {
+	run Runner, say func(string)) (apply.Report, error) {
 
 	// Refuse a shape this host cannot apply before anything is applied, exactly as `mesh-host`
 	// does: finding out half way through is the half-configured machine tier 0 exists to prevent.