vdoc: cleanup node.v

[ttytm]

Pushing the fix for the vdoc sorting issue on non linux after this one to enable tests there as well.

[spytheman]

Good find.

[spytheman]

rg '\.keys\(\).map\(' returned a few more potential candidates:

#0 18:56:57 ᛋ master /v/oo❱rg '\.keys\(\).map\('
vlib/net/http/header.v:504:new_keys := arrays.distinct(h.keys().map(it.to_lower()))
vlib/v/doc/node.v:51:mut contents := cnts.keys().map(cnts[it])
vlib/v/tests/map_literals_method_call_test.v:4:}.keys().map({
vlib/v/tests/bench/math_big_gcd/prime/maker.v:176:return tmp.keys().map(tmp[it])
cmd/tools/vdoc/vdoc.v:64:jw.write_string(json.encode(d.contents.keys().map(d.contents[it])))
#0 16:21:05 ᛋ master /v/oo❱

[spytheman]

Excellent work.