[ci-doctor]: Fix repo checkout (openvinotoolkit#3621)

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## Description
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motivation and context. -->

After adding conditional PR commit checkout `gh aw compile` removed
unconditional repo checkout from `.lock.yml`:
https://github.com/openvinotoolkit/openvino.genai/actions/runs/23786362854/job/69310573077#step:4:16.
Re-add repo checkout to `.md` file.

Fixes: openvinotoolkit#3620

## Checklist:
- [x] This PR follows [GenAI Contributing
guidelines](https://github.com/openvinotoolkit/openvino.genai?tab=contributing-ov-file#contributing).
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Author: as-suvorov

.github/workflows/ci-doctor.lock.yml

@@ -47,6 +47,14 @@ tools:
 timeout-minutes: 10
 
 steps:
+  - name: Checkout repository
+    uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    with:
+      persist-credentials: false
+  - name: Setup Python
+    uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+    with:
+      python-version: "3.12"
   - name: Install Python requirements for CI Doctor
     run: pip install -r .github/scripts/ci-doctor/requirements.txt