Local dependencies prevent the google cloud function from building #276

Issue description
I'm trying to implement code sharing between multiple services by using npm local dependencies. Here is the code structure:

endpoints
-servicename
--package.json
--serverless.yml

libs
-database.js
-auth.js
-package.json

I've added the libs folder as a local dependency to my function like so:

"dependencies": { "libs": "../../libs" }

When the cloud build is initiated for deployment, I get an error shown below during deployment:

Build failed: npm ERR! code EEXIST
npm ERR! syscall mkdir
npm ERR! path /workspace/node_modules/libs
npm ERR! errno -17
npm ERR! EEXIST: file already exists, mkdir '/workspace/node_modules/libs'
npm ERR! File exists: /workspace/node_modules/libs
npm ERR! Remove the existing file and try again, or run npm
npm ERR! with --force to overwrite files recklessly.

Service configuration (serverless.yml) content

service: servicename

provider:
  name: google
  stage: dev
  runtime: nodejs14
  region: asia-south1
  project: project-name
  credentials: "../../creds.json"

frameworkVersion: '2'

plugins:
  - serverless-google-cloudfunctions

package:
  exclude:
    - node_modules/**
    - .gitignore
    - .git/**

functions:
  get:
    handler: servicehandler
    events:
      - http: path

Command name and used flags
serverless deploy --region asia-south1

Environment information
Framework Core: 2.59.0
Plugin: 5.4.4
SDK: 4.3.0
Components: 3.17.1