chore(ci): Pin GitHub Actions to commit SHAs

Pin GitHub Actions references to full commit SHAs instead of version
tags to reduce supply chain risk from tag retargeting.

Update actions/checkout to v6.0.2, actions/setup-python to v6.2.0,
actions/setup-node to v6.3.0, actions/stale to v10.2.0, and
dessant/lock-threads to v6.0.0.

.github/workflows/ci.yml

@@ -53,7 +53,7 @@ jobs:
 
     steps:
     - name: Check out repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
     - name: Check Python linting & PEP8 compliance
       uses: astral-sh/ruff-action@4919ec5cf1f49eff0871dbcea0da843445b837e6 # v3.6.1
@@ -63,12 +63,12 @@ jobs:
         src: "netbox/"
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
       with:
         python-version: ${{ matrix.python-version }}
 
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
       with:
         node-version: ${{ matrix.node-version }}
     
@@ -76,7 +76,7 @@ jobs:
       run: npm install -g yarn
     
     - name: Setup Node.js with Yarn Caching
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
       with:
         node-version: ${{ matrix.node-version }}
         cache: yarn