examples/out_of_tree: Correct pipx argument order in the README #1916

Job	Run time
build-firmware	23s
build-manual	36s
test-software (3.9.5, deps: minimal)	1m 16s
test-software (3.9.5, deps: latest)	1m 25s
test-software (3.9.x, deps: minimal)	1m 12s
test-software (3.9.x, deps: latest)	1m 24s
test-software (3.10.x, deps: minimal)	1m 14s
test-software (3.10.x, deps: latest)	1m 12s
test-software (3.11.x, deps: minimal)	1m 0s
test-software (3.11.x, deps: latest)	1m 12s
test-software (3.12.x, deps: minimal)	1m 6s
test-software (3.12.x, deps: latest)	1m 9s
test-software (pypy-3.9, deps: minimal)	1m 32s
test-software (pypy-3.9, deps: latest)	1m 30s
test-software (pypy-3.10, deps: minimal)	1m 24s
test-software (pypy-3.10, deps: latest)	1m 27s
test-software (3.13-dev, deps: minimal)	1m 33s
test-software (3.13-dev, deps: latest)	1m 17s
publish-manual	0s
required	1s
	21m 53s

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