fix: identify dependencies that might require the --no-tree-shake-icons flag

[emwp]

Description

Related to this issue: #6197
Trying to identify dependencies that might require the --no-tree-shake-icons build flag.

Unfortunately can not allow users to pass arbitrary/custom flags when running the deploy function, so tried to identify dependencies that are likely to require the flag to build.

Scenarios Tested

• Building with dependencies that would add the flag to the build command.
• Building with no dependencies that would add the flag to the build command.

fixes #6197

[leoortizz]

we should use a path relative to the project root as the project can be located in a subdir, as we do in discover

firebase-tools/src/frameworks/flutter/index.ts

Lines 16 to 20 in cc6744f

	export async function discover(dir: string): Promise<Discovery | undefined> {
	if (!(await pathExists(join(dir, "pubspec.yaml")))) return;
	if (!(await pathExists(join(dir, "web")))) return;
	const pubSpecBuffer = await readFile(join(dir, "pubspec.yaml"));
	const pubSpec = yaml.parse(pubSpecBuffer.toString());

[leoortizz]

I think we can make it generic like getAdditionalBuildArgs and make it return an array of strings, then we can accommodate more use cases in the future if needed