Pin Python version for code quality checks. (#2674)

* Pin Python version for code quality checks. 

pin python version on public runners. 
https://github.com/runtimeverification/evm-semantics/actions/runs/12629580595/job/35187761558#step:4:86

Public runners use python version determined by Github.

* Update `copytree` function to support Python 3.12 (#2672)

* Update `copytree` dependency

* Allow copying to an existing dir

* Make the copied plugin directory readable and writeable

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Co-authored-by: Freeman <105403280+F-WRunTime@users.noreply.github.com>

Author: palinatolmach

.github/workflows/test-pr.yml

@@ -12,6 +12,10 @@ jobs:
     name: 'Code Quality Checks'
     runs-on: ubuntu-latest
     steps:
+      - name: 'Setup Python 3.10'
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.10'
       - name: 'Check out code'
         uses: actions/checkout@v4
       - name: 'Install Poetry'