fix(ssr): viteResolve fallback to absolute id

[natemoo-re]

Description

Adds fallback to viteResolve logic to just return absolute ids if tryNodeResolve doesn't return a match.

Astro's test suite is down to a single failure with this change.

Additional context

Astro is attempting to upgrade to vite@2.7.x but we've been hitting failures in CI. Because Vite is hooking require for SSR, all resolution is running through Vite for these tests.

This PR modifies still runs tryNodeResolve, but if a Vite-specific match is not found and the path is already absolute, we just fallback to the absolute path.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[natemoo-re]

Note that tryNodeResolve runs first, but won't return a match.

The problematic id is already a fully resolved, absolute path to a file that does exist... maybe this needs to be fixed inside of tryNodeResolve?

[aleclarson]

maybe this needs to be fixed inside of tryNodeResolve?

Vite's internal resolve plugin checks for absolute paths before tryNodeResolve. See here:

vite/packages/vite/src/node/plugins/resolve.ts

Lines 195 to 199 in b45f4ad

	// absolute fs paths
	if (path.isAbsolute(id) && (res = tryFsResolve(id, options))) {
	isDebug && debug(`[fs] ${colors.cyan(id)} -> ${colors.dim(res)}`)
	return res
	}

[natemoo-re]

Attempt: if tryNodeResolve returns undefined but our id is an absolute path, it might be fully resolved already. Just return it.

[aleclarson]

Any reason we shouldn't check for absolute path before the tryNodeResolve call?

[btakita]

Does #5495 also fix the issue with absolute paths?

[bluwy]

@natemoo-re It looks like #6488 is solving the same issue as this. Is this still needed?

(I forgot about this PR when making my fix there 😅)