ci: drop the schedule triggers, race and fuzz run on dispatch alone

Assisted-by: GLM 5.3

.gitea/workflows/fuzz.yml

@@ -1,20 +1,16 @@
-# Fuzz smoke, Go. A nightly time-boxed run of the fuzz targets, and a hand
-# dispatch when a change asks for it.
+# Fuzz smoke, Go. Dispatched by hand when a change asks for it.
 #
 # Fuzzing is exploration, so it never belongs to the push pipeline; a 30 second
-# smoke per target, run nightly, is the compromise that catches a new crash
-# within a day without holding the shared box. The targets run the seeds and
-# whatever the corpus has gathered; a failure leaves its crashing input in
-# testdata/fuzz, which the ordinary suite then reproduces on every push.
+# smoke per target on a hand dispatch checks a change without holding the
+# shared box. The targets run the seeds and whatever the corpus has gathered; a
+# failure leaves its crashing input in testdata/fuzz, which the ordinary suite
+# then reproduces on every push.
 #
 # Every step is one command, so the step that fails is the gate that failed.
 name: Fuzz
 
 on:
   workflow_dispatch:
-  schedule:
-    # Nightly at 03:30 UTC, after the race sweep has had the box first.
-    - cron: "30 3 * * *"
 
 env:
   # One core: parallelism buys no speed here and costs memory the box does not have.