fix: resolve workspace paths from cwd when possible

[nlf]

these are changes that are required along with landing and publishing npm/config#28 (and updating it here) to enable automatic detection of a workspace root.

this fix stands on its own, however. if a user had the structure

/package.json
/workspaces/a/package.json

and they ran npm test -w ./a from within /workspaces/, they would currently get an error. this corrects that behavior so we resolve the path for a based on process.cwd() instead of the workspace root.

to disable this feature currently a user must run npm --prefix=./ npm --no-workspaces to skip the prefix auto detection. the workspaces flag must be part of the environment or command line flags and not in a file to work.

the above comment is not directly related to this pull request, but i wanted to keep it here for posterity

[ljharb]

Would this encourage use of prefix in npmrc or the env? using prefix breaks nvm and sometimes termux, so it’d be ideal not to increase usage of it.

[npm-robot]

found 20 benchmarks with statistically significant performance improvements

• app-large: clean, lock-only, cache-only, cache-only:peer-deps, modules-only, no-lock, no-cache, no-modules, no-clean, no-clean:audit
• app-medium: clean, lock-only, cache-only, cache-only:peer-deps, modules-only, no-lock, no-cache, no-modules, no-clean, no-clean:audit

timing results

app-large	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	57.522 ±1.47	30.050 ±0.14	28.970 ±16.03	19.818 ±1.51	2.787 ±0.01	2.995 ±0.06	2.408 ±0.02	11.233 ±0.25	2.310 ±0.03	3.168 ±0.01
#4265	0.394 ±0.00	0.393 ±0.00	0.392 ±0.00	0.386 ±0.01	0.387 ±0.00	0.392 ±0.01	0.394 ±0.01	0.393 ±0.00	0.391 ±0.00	0.426 ±0.02

app-medium	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	40.191 ±4.28	22.135 ±0.10	12.959 ±0.85	13.651 ±0.27	2.549 ±0.02	2.519 ±0.03	2.820 ±0.84	8.479 ±0.44	2.232 ±0.02	3.006 ±0.03
#4265	0.444 ±0.02	0.428 ±0.00	0.422 ±0.01	0.390 ±0.00	0.387 ±0.00	0.388 ±0.00	0.396 ±0.00	0.390 ±0.00	0.390 ±0.00	0.389 ±0.00

[nlf]

Would this encourage use of prefix in npmrc or the env? using prefix breaks nvm and sometimes termux, so it’d be ideal not to increase usage of it.

very valid point. i've tweaked the changes to @npmcli/config so that --no-workspaces on the cli will also disable this check

[nlf]

moved to ready for review since this can land independently of the @npmcli/config changes (but needs to land before updating @npmcli/config)

[ruyadorno]

relates to: npm/rfcs#343