Refactor: Simplify `@syms` macro implementation

[bowenszhu]

This PR removes redundant call to _name_type within the @syms macro definition.

[github-actions[bot]]

Benchmark Results

	master	52e364d183c29f...	master/52e364d183c29f...
overhead/acrule/a+2	0.786 ± 0.02 μs	0.744 ± 0.015 μs	1.06
overhead/acrule/a+2+b	0.76 ± 0.017 μs	0.736 ± 0.018 μs	1.03
overhead/acrule/a+b	0.261 ± 0.0077 μs	0.285 ± 0.0061 μs	0.915
overhead/acrule/noop:Int	25 ± 0.06 ns	25.7 ± 0.12 ns	0.976
overhead/acrule/noop:Sym	0.0364 ± 0.0052 μs	0.0501 ± 0.0056 μs	0.726
overhead/rule/noop:Int	0.044 ± 0.00099 μs	0.0441 ± 0.0012 μs	0.997
overhead/rule/noop:Sym	0.0547 ± 0.0023 μs	0.0548 ± 0.0024 μs	0.997
overhead/rule/noop:Term	0.0545 ± 0.0023 μs	0.0545 ± 0.0021 μs	1
overhead/ruleset/noop:Int	0.132 ± 0.0039 μs	0.133 ± 0.0029 μs	0.995
overhead/ruleset/noop:Sym	0.152 ± 0.0038 μs	0.159 ± 0.0039 μs	0.959
overhead/ruleset/noop:Term	3.85 ± 0.14 μs	3.69 ± 0.14 μs	1.04
overhead/simplify/noop:Int	0.138 ± 0.0033 μs	0.145 ± 0.0035 μs	0.95
overhead/simplify/noop:Sym	0.154 ± 0.0051 μs	0.155 ± 0.0038 μs	0.993
overhead/simplify/noop:Term	0.0378 ± 0.0019 ms	0.0402 ± 0.0021 ms	0.94
overhead/simplify/randterm (+, *):serial	0.121 ± 0.005 s	0.12 ± 0.0053 s	1.01
overhead/simplify/randterm (+, *):thread	0.0743 ± 0.022 s	0.0753 ± 0.023 s	0.987
overhead/simplify/randterm (/, *):serial	0.225 ± 0.0068 ms	0.231 ± 0.007 ms	0.974
overhead/simplify/randterm (/, *):thread	0.256 ± 0.0077 ms	0.264 ± 0.0078 ms	0.968
overhead/substitute/a	0.0617 ± 0.0016 ms	0.0587 ± 0.0015 ms	1.05
overhead/substitute/a,b	0.0544 ± 0.0015 ms	0.0516 ± 0.0015 ms	1.06
overhead/substitute/a,b,c	17.8 ± 0.69 μs	17.2 ± 0.66 μs	1.04
polyform/easy_iszero	0.0345 ± 0.0018 ms	0.0333 ± 0.0018 ms	1.04
polyform/isone	2.79 ± 0.01 ns	2.79 ± 0.01 ns	0.997
polyform/iszero	1.81 ± 0.035 ms	1.76 ± 0.037 ms	1.03
polyform/simplify_fractions	2.43 ± 0.039 ms	2.38 ± 0.048 ms	1.02
time_to_load	4.58 ± 0.016 s	4.56 ± 0.017 s	1

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR. Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).