feat: allow overwrite the path for the downloads folder

[fengmk2]

e.g.:

PUPPETEER_DOWNLOAD_PATH=/store/chromiums npm install

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[fengmk2]

@googlebot I signed it!

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[lcabral37]

I'm guessing this PR is dead in the water?
Anyhow an advice, it would be nice to share the PUPPETEER_DOWNLOAD_PATH to the launcher as well as to not having to keep track of it via the PUPPETEER_DOWNLOAD_PATH.
something like (you should take in consideration that you might not want to expose this to puppeteer-core):

@@ -743,11 +743,15 @@ function resolveExecutablePath(
   }
   const browserFetcher = new BrowserFetcher(launcher._projectRoot, {
     product: launcher.product,
+    path: process.env.PUPPETEER_DOWNLOAD_PATH ||
+      process.env.npm_config_puppeteer_download_path ||
+      process.env.npm_package_config_puppeteer_download_path,
   });
   if (!launcher._isPuppeteerCore && launcher.product === 'chrome') {

Independently of this PR turns out, great work

[jschfflr]

@fengmk2 Thanks for your contribution! Could you verify it's still relevant and update it to resolve the merge conflicts? Happy to get this landed :)

[jschfflr]

This functionality has already landed in #6014. But thanks for your contribution anyways!

[fengmk2]

@jschfflr :)