build: ensure fetching from upstream repository and not fork

Author: Planeshifter

.github/workflows/pr_merge_develop.yml

@@ -108,8 +108,18 @@ jobs:
           BRANCH_NAME: ${{ steps.pr-details.outputs.branch }}
           REPO_NAME: ${{ steps.pr-details.outputs.repository }}
         run: |
+          # Configure Git user:
           git config --local user.email "[email protected]"
           git config --local user.name "stdlib-bot"
-          git fetch origin develop:develop
-          git merge develop --no-edit
+
+          # Add upstream remote pointing to the original repository:
+          git remote add upstream https://github.com/stdlib-js/stdlib.git
+
+          # Fetch the develop branch from upstream:
+          git fetch upstream develop
+
+          # Merge upstream develop into the current branch:
+          git merge upstream/develop --no-edit
+
+          # Push the updated branch back to the forked repository:
           git push "https://$USER_NAME:[email protected]/$REPO_NAME.git" $BRANCH_NAME

.github/workflows/pr_rebase_develop.yml

@@ -108,8 +108,18 @@ jobs:
           BRANCH_NAME: ${{ steps.pr-details.outputs.branch }}
           REPO_NAME: ${{ steps.pr-details.outputs.repository }}
         run: |
+          # Configure Git user:
           git config --local user.email "[email protected]"
           git config --local user.name "stdlib-bot"
-          git fetch origin develop:develop
-          git rebase develop
+
+          # Add upstream remote pointing to the original repository:
+          git remote add upstream https://github.com/stdlib-js/stdlib.git
+
+          # Fetch the develop branch from upstream:
+          git fetch upstream develop
+
+          # Rebase current branch onto upstream develop:
+          git rebase upstream/develop
+
+          # Force push the updated branch back to the forked repository:
           git push --force-with-lease "https://$USER_NAME:[email protected]/$REPO_NAME.git" $BRANCH_NAME