[BUG] [3.1.2] Fail to esinstall node_modules files with .svg extensions

[harleylang]

Bug Report Quick Checklist

• I am on the latest version of Snowpack & all plugins.
• I use package manager npm (Fill in: npm, yarn, pnpm, etc).
• I run Snowpack on OS Linux (Fill in: Windows, Mac, Linux, etc).
• I run Snowpack on Node.js v12+

Describe the bug

After upgrading from 3.0.11 to 3.1.2 I am receiving an esinstall error after running npm run dev:

[13:41:17] [snowpack] + {internal-private-package}
[13:41:17] [esinstall:{the-private-package}] Failed to load ../dist/icons/{filename}.svg
Unexpected token (Note that you need plugins to import files that are not JavaScript)
[13:41:17] [snowpack] Install failed.

When I comment out the imports for that SVG file, I am also receiving errors described in #2970 for .scss extensions.

To Reproduce

Import a private npm package that includes a file that imports an .svg file.

Use the following config:

module.exports = {
    mount: {
      public: { url: '/', static: true },
      src: { url: '/dist' },
    },
    extends: "@snowpack/app-scripts-react",

//...

    plugins: [
      "@snowpack/plugin-sass",
      "snowpack-plugin-mdx"
    ],
    packageOptions: {
      external: [
        "@material-ui/core/OverridableComponent", 
        "node_modules/bootstrap/scss/_functions",
        "node_modules/bootstrap/scss/_variables",
        "node_modules/bootstrap/scss/_mixins",
        "node_modules/bootstrap/scss/_progress",
        "node_modules/bootstrap/scss/_utilities",
      ],
      rollup: {
        plugins: [
          require('@rollup/plugin-typescript')(),
          require("rollup-plugin-node-polyfills")(),
          require("rollup-plugin-scss")(),
          require("rollup-plugin-svg")()
        ],
      },
  },
}

Expected behavior

Expecting the initial snowpack caching to complete and to proceed with serving my React application.

I have temporarily downgraded to 3.0.11 and everything works as expected.

[harleylang]

Reporting back; fixed with #3123.