Run benchmarks with --steps=2 (#5853)

The benchmarks have been run internally with at least two values
even when called with --steps=1. substrate/#11890 changed this
to explicitly require at least --steps=2.

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

polkadot/.gitlab-ci.yml

@@ -925,20 +925,17 @@ short-benchmark-polkadot:          &short-bench
   variables:
     RUNTIME:                       polkadot
   script:
-    - ./artifacts/polkadot benchmark pallet --execution wasm --wasm-execution compiled --chain $RUNTIME-dev --pallet "*" --extrinsic "*" --steps 1 --repeat 1
-  allow_failure:                   true
+    - ./artifacts/polkadot benchmark pallet --execution wasm --wasm-execution compiled --chain $RUNTIME-dev --pallet "*" --extrinsic "*" --steps 2 --repeat 1
 
 short-benchmark-kusama:
   <<:                              *short-bench
   variables:
     RUNTIME:                       kusama
-  allow_failure:                   true
 
 short-benchmark-westend:
   <<:                              *short-bench
   variables:
     RUNTIME:                       westend
-  allow_failure:                   true
 
 #### stage:                        .post