You need to use the proper git URL:

pip install git+https://github.com/jkbr/httpie.git#egg=httpie

Also see the VCS Support section of the pip documentation.

Don’t forget to include the egg=<projectname> part to explicitly name the project; this way pip can track metadata for it without having to have run the setup.py script.

I was facing the same issue, I found out that according to this GCP Documentation, I didn't have keyring and keyrings.google-artifactregistry-auth installed,

1. Try installing these two packages in the step where you install your python packages.
2. Make sure that your service account has required permissions
3. Make sure you give read and write permissions in your workflow file.

Example Workflow,

name: Example Workflow
on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main

permissions:
  id-token: write
  contents: read

jobs:
   runs-on: ubuntu-latest
   steps:
     - uses: actions/checkout@v3
       with:
         fetch-depth: 2

     - name: Authenticate to Google Cloud
       id: gcloud_auth
       uses: google-github-actions/auth@v2
       with:
         token_format: 'access_token'
         workload_identity_provider: 'projects/<PROJECT_ID>/locations/global/workloadIdentityPools/github-pool/providers/example-github-provider'
         service_account: '[email protected]'

     - name: Install dependencies
       id: install_dependencies
       run: |
            python -m pip install keyrings.google-artifactregistry-auth
            pip install --extra-index-url https://europe-west9-python.pkg.dev/path-to/simple/ PACKAGE

I hope this helps!