chore: tame some slow benchmarks (#8352)

No single-topic benchmark should take half as long as stdlib.

Bench run time reduced from 27min to 21min.

Author: Kha

tests/bench/channel.lean

@@ -21,7 +21,7 @@ Note that we will stick exclusively to the sync interface for this as there is n
 reaped from async in this benchmark so we might as well just block.
 -/
 
-def MESSAGES : Nat := 1_000_000
+def MESSAGES : Nat := 100_000
 def THREADS : Nat := 4
 
 def seq (ch : Std.CloseableChannel.Sync Nat) (amount : Nat) : IO Unit := do

tests/bench/speedcenter.exec.velcom.yaml

@@ -145,7 +145,7 @@
         lean --run ${f%.args} $(cat $f)
       done
       '
-    max_runs: 5
+    max_runs: 2
 - attributes:
     description: binarytrees
     tags: [fast, suite]
@@ -191,6 +191,7 @@
       lake -flakefile-clean.lean clean
       lake -flakefile-clean.lean build
       "
+    max_runs: 2
   build_config:
     cmd: |
       bash -c "
@@ -412,6 +413,7 @@
   run_config:
     <<: *time
     cmd: lean workspaceSymbols.lean
+    max_runs: 2
 - attributes:
     description: bv_decide_realworld
     tags: [fast]
@@ -430,12 +432,14 @@
   run_config:
     <<: *time
     cmd: lean bv_decide_mod.lean
+    max_runs: 2
 - attributes:
     description: bv_decide_inequality.lean
     tags: [fast]
   run_config:
     <<: *time
     cmd: lean bv_decide_inequality.lean
+    max_runs: 2
 - attributes:
     description: bv_decide_large_aig.lean
     tags: [fast]
@@ -481,3 +485,4 @@
   run_config:
     <<: *time
     cmd: lean riscv-ast.lean
+    max_runs: 2