build(deps-dev): Bump virtualenv

Bumps the pip group with 1 update in the /requirements directory: [virtualenv](https://github.com/pypa/virtualenv).


Updates `virtualenv` from 20.26.1 to 20.26.6
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.26.1...20.26.6)

---
updated-dependencies:
- dependency-name: virtualenv
  dependency-type: direct:development
  dependency-group: pip
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements/requirements_dev.txt

@@ -982,9 +982,9 @@ typing-extensions==4.11.0 ; python_version >= "3.9" and python_version < "4.0" \
 urllib3==2.2.1 ; python_version >= "3.9" and python_version < "4.0" \
     --hash=sha256:450b20ec296a467077128bff42b73080516e71b56ff59a60a02bef2232c4fa9d \
     --hash=sha256:d0570876c61ab9e520d776c38acbbb5b05a776d3f9ff98a5c8fd5162a444cf19
-virtualenv==20.26.1 ; python_version >= "3.9" and python_version < "4.0" \
-    --hash=sha256:604bfdceaeece392802e6ae48e69cec49168b9c5f4a44e483963f9242eb0e78b \
-    --hash=sha256:7aa9982a728ae5892558bff6a2839c00b9ed145523ece2274fad6f414690ae75
+virtualenv==20.26.6 ; python_version >= "3.9" and python_version < "4.0" \
+    --hash=sha256:280aede09a2a5c317e409a00102e7077c6432c5a38f0ef938e643805a7ad2c48 \
+    --hash=sha256:7345cc5b25405607a624d8418154577459c3e0277f5466dd79c49d5e492995f2
 wcwidth==0.2.13 ; python_version >= "3.9" and python_version < "4.0" \
     --hash=sha256:3da69048e4540d84af32131829ff948f1e022c1c6bdb8d6102117aac784f6859 \
     --hash=sha256:72ea0c06399eb286d978fdedb6923a9eb47e1c486ce63e9b4e64fc18303972b5