test: unpin m6i/5.10 AMI for perf tests

With C-states renabled by f610cae ("fix: stop messing with C-states
in performance tests"), the m6i volatility will be gone.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

.buildkite/pipeline_perf.py

@@ -121,10 +121,7 @@
 # }
 # will pin steps running on instances "m6i.metal" with kernel version tagged "linux_6.1"
 # to a new kernel version tagged "linux_6.1-pinned"
-pins = {
-    # TODO: Unpin when performance instability on m6i/5.10 has gone.
-    "linux_5.10-pinned": {"instance": "m6i.metal", "kv": "linux_5.10"},
-}
+pins = {}
 
 
 def apply_pins(steps):