fix: debug throwing in valid nested table

[marvinhagemeister]

Although discouraged for accessibility reasons, it is valid to nest tables inside tables for as long as the full table structure is used. See https://developer.mozilla.org/en-US/docs/Learn/HTML/Tables/Advanced#nesting_tables

We'd previously throw an error on this.

[github-actions]

Size Change: +62 B (0%)

Total Size: 57.4 kB

Filename	Size	Change
debug/dist/debug.js	3.52 kB	+20 B (0%)
debug/dist/debug.module.js	3.52 kB	+21 B (0%)
debug/dist/debug.umd.js	3.6 kB	+21 B (0%)

ℹ️ View Unchanged

Filename	Size	Change
compat/dist/compat.js	3.97 kB	0 B
compat/dist/compat.module.js	3.9 kB	0 B
compat/dist/compat.umd.js	4.04 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	315 B	0 B
dist/preact.js	4.42 kB	0 B
dist/preact.min.js	4.46 kB	0 B
dist/preact.min.module.js	4.45 kB	0 B
dist/preact.min.umd.js	4.48 kB	0 B
dist/preact.module.js	4.45 kB	0 B
dist/preact.umd.js	4.49 kB	0 B
hooks/dist/hooks.js	1.53 kB	0 B
hooks/dist/hooks.module.js	1.56 kB	0 B
hooks/dist/hooks.umd.js	1.62 kB	0 B
jsx-runtime/dist/jsxRuntime.js	365 B	0 B
jsx-runtime/dist/jsxRuntime.module.js	331 B	0 B
jsx-runtime/dist/jsxRuntime.umd.js	445 B	0 B
test-utils/dist/testUtils.js	453 B	0 B
test-utils/dist/testUtils.module.js	454 B	0 B
test-utils/dist/testUtils.umd.js	536 B	0 B

_{compressed-size-action}

[coveralls]

coverage: 99.429% (-0.001%) from 99.43%
when pulling e471ce1 on debug-nested-tables
into 9a9967d on main.