Remove unnecessary hardcoding of ref (#1456)

I'm copying the setup of one of these actions to another repo, and the hardcoding of ref surprised me... these should be the same as the defaault behavior. I checked with Barry who originally committed these files, and he didn't remember why... possibly he'd hardcoded them when testing the action and forgot to remove them.

So let's pull them out to remove confusion.

Author: jeffwidman

Diff for: .github/workflows/check-dist.yml

@@ -13,8 +13,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
@@ -33,8 +31,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
 
       - uses: ./
         with:

Diff for: .github/workflows/codeql-analysis.yml

@@ -24,8 +24,6 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-      with:
-        ref: ${{ github.event.pull_request.head.sha }}
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v3

Diff for: .github/workflows/integration-test.yml

@@ -14,8 +14,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Setup Node.js
         uses: actions/setup-node@v4

Diff for: .github/workflows/test.yml

@@ -12,8 +12,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Setup Node.js
         uses: actions/setup-node@v4