Crowdin Action fails to detect existing pull request when using a non-main base branch and same-repo source branch

[casper-mercell]

Describe the bug
When the base branch for the pull request is not main (e.g., develop), the Crowdin GitHub Action fails to detect an existing pull request from a same-repo source branch (e.g., l10n_crowdin_translations). As a result, it attempts to create a new pull request and fails with a 422 Validation Failed error.

The issue likely occurs because the action uses head=ORG_NAME:BRANCH when calling the GitHub API to check for existing PRs.

To Reproduce
Steps to reproduce the behavior:

1. Use the Crowdin GitHub Action with the following relevant configuration:

localization_branch_name: l10n_crowdin_translations
pull_request_base_branch_name: develop
create_pull_request: true

2. Ensure that:

• A pull request already exists from l10n_crowdin_translations to develop
• Both branches exist in the same repository (not from a fork)

3. Trigger the workflow again (either via schedule or manual dispatch)

Example workflow:

name: Crowdin Action Pull

on:
  workflow_dispatch:
  schedule:
    - cron: '0 7,12 * * *'

jobs:
  synchronize-with-crowdin:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: crowdin action
        uses: crowdin/github-action@v2
        with:
          upload_sources: false
          upload_translations: false
          download_sources: true
          download_translations: true
          export_only_approved: true
          localization_branch_name: l10n_crowdin_translations
          pull_request_base_branch_name: develop
          create_pull_request: true
          push_sources: true
          push_translations: true
          pull_request_title: 'New Crowdin Translations'
          pull_request_body: 'New Crowdin translations by [Crowdin GH Action](https://github.com/crowdin/github-action)'
          pull_request_labels: 'Crowdin'
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          CROWDIN_PROJECT_ID: ${{ secrets.CROWDIN_PROJECT_ID }}
          CROWDIN_PERSONAL_TOKEN: ${{ secrets.CROWDIN_PERSONAL_TOKEN }}

Expected behavior
The action should detect that a pull request from l10n_crowdin_translations to develop already exists and skip creating a new one. It should log PULL REQUEST ALREADY EXIST instead of failing.

Screenshots
Relevant log from the failing repo:

PUSH TO BRANCH l10n_crowdin_translations
[l10n_crowdin_translations 5b7daab] New Crowdin translations by GitHub Action
 1 file changed, 21 insertions(+), 21 deletions(-)
To https://github.com/XXX/YYY.git
 + 27f2ff2...5b7daab l10n_crowdin_translations -> l10n_crowdin_translations (forced update)
CHECK IF PULL REQUEST ALREADY EXIST
CREATE PULL REQUEST
FAILED TO CREATE PULL REQUEST
RESPONSE: {
  "message": "Validation Failed",
  "errors": [
    {
      "resource": "PullRequest",
      "code": "custom",
      "message": "A pull request already exists for XXX:l10n_crowdin_translations."
    }
  ],
  "documentation_url": "https://docs.github.com/rest/pulls/pulls#create-a-pull-request",
  "status": "422"
}

Additional context
The bug appears in this part of the Crowdin action logic:

pull_requests_response=$(curl ... "${PULLS_URL}?base=${BASE_BRANCH}&head=${ORG_NAME}:${BRANCH}")

When changing into it works

"${PULLS_URL}?base=${BASE_BRANCH}&head=${BRANCH}"

I've verified this by forking the action and applying the fix — and the problem was resolved. The action correctly detects existing pull requests and avoids trying to create duplicates.