Add unkeyed swap test for issue #2949

[marvinhagemeister]

Don't have a fix for it yet, but figured the test case is good to have in our suite regardless until we find a fix.

[coveralls]

Coverage remained the same at 99.44% when pulling 492261a on unkeyed-swap-test into 359ad4f on master.

[github-actions]

Size Change: 0 B

Total Size: 42.1 kB

ℹ️ View Unchanged

Filename	Size	Change
compat/dist/compat.js	3.45 kB	0 B
compat/dist/compat.module.js	3.47 kB	0 B
compat/dist/compat.umd.js	3.51 kB	0 B
debug/dist/debug.js	2.99 kB	0 B
debug/dist/debug.module.js	2.98 kB	0 B
debug/dist/debug.umd.js	3.07 kB	0 B
devtools/dist/devtools.js	232 B	0 B
devtools/dist/devtools.module.js	240 B	0 B
devtools/dist/devtools.umd.js	308 B	0 B
dist/preact.js	3.93 kB	0 B
dist/preact.min.js	3.96 kB	0 B
dist/preact.module.js	3.96 kB	0 B
dist/preact.umd.js	4 kB	0 B
hooks/dist/hooks.js	1.13 kB	0 B
hooks/dist/hooks.module.js	1.15 kB	0 B
hooks/dist/hooks.umd.js	1.2 kB	0 B
jsx-runtime/dist/jsxRuntime.js	327 B	0 B
jsx-runtime/dist/jsxRuntime.module.js	335 B	0 B
jsx-runtime/dist/jsxRuntime.umd.js	405 B	0 B
test-utils/dist/testUtils.js	437 B	0 B
test-utils/dist/testUtils.module.js	439 B	0 B
test-utils/dist/testUtils.umd.js	515 B	0 B

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