Incorrect import path for output entries in metadata

[evanleck]

When writing out a metadata file, the imports -> path fields are wrong and appear to have doubled the --public-path value. Seems like this may be related to #524, but either way I've put together a reproduction repository. Pull that down, run npm install and then this command (it's also in the repro repo):

npx esbuild --metafile=meta.json --public-path=assets --bundle --format=esm --splitting --outdir=assets index.js other.js

And take a look at the metafile's contents. You'll see that each outputs entry's imports path look like assets/assets/chunk* where it should only include assets once.

{
  "inputs": {
    "index.js": {
      "bytes": 46,
      "imports": [
        {
          "path": "log.js"
        }
      ]
    },
    "log.js": {
      "bytes": 54,
      "imports": []
    },
    "other.js": {
      "bytes": 44,
      "imports": [
        {
          "path": "log.js"
        }
      ]
    }
  },
  "outputs": {
    "assets/index.js": {
      "imports": [
        {
          "path": "assets/assets/chunk.STFGGPZ3.js"
        }
      ],
      "exports": [],
      "inputs": {
        "index.js": {
          "bytesInOutput": 16
        }
      },
      "bytes": 79
    },
    "assets/other.js": {
      "imports": [
        {
          "path": "assets/assets/chunk.STFGGPZ3.js"
        }
      ],
      "exports": [],
      "inputs": {
        "other.js": {
          "bytesInOutput": 14
        }
      },
      "bytes": 77
    },
    "assets/chunk.STFGGPZ3.js": {
      "imports": [],
      "exports": [
        "log"
      ],
      "inputs": {
        "log.js": {
          "bytesInOutput": 50
        }
      },
      "bytes": 79
    }
  }
}