fix: examples/io/vuln_export_csv_writer/requirements.txt to reduce vu…

…lnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-REQUESTS-6928867

examples/io/vuln_export_csv_writer/requirements.txt

@@ -1,2 +1,3 @@
 click>=7.0
-pytenable>=0.3.15
+pytenable>=0.3.15
+requests>=2.32.0 # not directly required, pinned by Snyk to avoid a vulnerability