[fix] run else-if reactive function on re-renders

[bluwy]

Fixes https://svelte.dev/repl/0a0f5241e099434ea22f5776d215b6b9?version=3.42.5. The repl should explain the issue.

This change also makes it consistent with the current "without outros" code:

svelte/src/compiler/compile/render_dom/wrappers/IfBlock.ts

Lines 273 to 274 in c040f13

	? b`if (${condition} == null || ${block.renderer.dirty(dependencies)}) ${condition} = !!${snippet}`
	: b`if (${condition} == null) ${condition} = !!${snippet}`

Currently "with outros" code:

svelte/src/compiler/compile/render_dom/wrappers/IfBlock.ts

Lines 394 to 395 in c040f13

	? b`if (${block.renderer.dirty(dependencies)}) ${condition} = !!${snippet}`
	: b`if (${condition} == null) ${condition} = !!${snippet}`

Note the missing ${condition} == null check.

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• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• Prefix your PR title with [feat], [fix], [chore], or [docs].
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with npm test and lint the project with npm run lint

[Conduitry]

This is included in 3.42.6 - thank you!