Revert "Fix checkout target for pull request workflows (#212)"

This reverts commit 9108369.

Author: sjmonson

.github/workflows/development.yml

@@ -12,8 +12,6 @@ jobs:
         python: ["3.9", "3.13"]
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
@@ -30,8 +28,6 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
 
       - name: Install dependencies
         run: npm ci
@@ -46,8 +42,6 @@ jobs:
         python: ["3.9", "3.13"]
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
@@ -64,8 +58,6 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
 
       - name: Install dependencies
         run: npm ci
@@ -80,8 +72,6 @@ jobs:
         python: ["3.9"]
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
@@ -98,8 +88,6 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
 
       - name: Install dependencies
         run: npm ci
@@ -114,8 +102,6 @@ jobs:
         python: ["3.9", "3.13"]
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
@@ -132,8 +118,6 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
 
       - name: Install dependencies
         run: npm ci
@@ -148,8 +132,6 @@ jobs:
         python: ["3.9", "3.13"]
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
@@ -165,9 +147,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@v4
-        with:
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
 
       - name: Install dependencies
         run: npm ci
@@ -185,7 +164,6 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
-          ref: "${{ github.event.pull_request.merge_commit_sha }}"
       - name: Set up Python
         uses: actions/setup-python@v5
         with: