Fix HIGH-level OpenSSF Scorecard code scanning alerts (VulnerabilitiesID) (#175)

* Fix HIGH-level code scanning alerts: pin safe dep versions, add fuzz tests

- Add urllib3>=2.6.3 and setuptools>=78.1.1 to requirements-test.txt to
  eliminate known vulnerabilities reported by the OpenSSF Scorecard's
  VulnerabilitiesID check (3 urllib3 vulns + 2 setuptools vulns fixed)
- Add fuzz/fuzz_paths.py and fuzz/fuzz_io.py using atheris to address the
  FuzzingID HIGH-level code scanning alert
- Add requirements-fuzz.txt with the atheris dependency

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Co-authored-by: fabiocaccamo <1035294+fabiocaccamo@users.noreply.github.com>

* Remove incorrectly added fuzz tests (FuzzingID is MEDIUM severity, not HIGH)

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Co-authored-by: fabiocaccamo <1035294+fabiocaccamo@users.noreply.github.com>

* Pin setuptools and urllib3 to exact versions in requirements-test.txt

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Co-authored-by: fabiocaccamo <1035294+fabiocaccamo@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: fabiocaccamo <1035294+fabiocaccamo@users.noreply.github.com>

Author: Copilot

requirements-test.txt

@@ -4,4 +4,6 @@ pre-commit == 4.5.*
 pytest == 9.0.*
 pytest-cov == 7.1.*
 requests == 2.33.*
+setuptools == 82.0.*
 tox == 4.52.*
+urllib3 == 2.6.*