(Windows probably has some way, but those are rarely discoverable.)
Released back in 2019 for Windows 10.
1. Install and configure this extra tool, which also by default enables a ton of other things you may not want, and may as well be a third-party tool even though it's technically built by Microsoft
2. Do a Google search and copy-paste (!)
3. Use a keyboard shortcut to bring up a symbol picker, then click on the tab containing the en and em dashes, then click to type them in
I mean, come on.
-- into —
If OP wrote their post on an iPhone, they would have inadvertently appeared as an LLM by their own test.
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[2] Though having checked just now, the sequences for en-dash and em-dash don't seem to be working. Perhaps one of my custom macros is interfering somehow… (it is behaving overall, ellipsis just worked as did the following diacritic and other symbols: áèîöūñ±⁰¹²∞¡¿‽π⬚). I'll have to poke at it later and see what is ary.
Of course, I guess it's entirely possible—even accounting for OS—that this test remains statistically useful. It makes me kinda sad that my (very much human-generated) writing fails the Turing test....