increase alloc test lower bound from 0.25x to 0.5x

perf/flame.jl

@@ -104,7 +104,7 @@ end
 
 # https://github.com/CliMA/ClimaAtmos.jl/issues/827
 @testset "Allocations limit" begin
-    @test 0.25 * allocs_limit[job_id] * buffer <=
+    @test 0.5 * allocs_limit[job_id] * buffer <=
           allocs ≤
           allocs_limit[job_id] * buffer
 end