Bump pygments from 2.12.0 to 2.15.0 in /src/Python

Bumps [pygments](https://github.com/pygments/pygments) from 2.12.0 to 2.15.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.12.0...2.15.0)

---
updated-dependencies:
- dependency-name: pygments
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/Python/requirements.txt

@@ -5,7 +5,7 @@ nbconvert==7.0.0
 notebook==6.5.2
 numpy==1.22.0
 pytest==7.2.0
-pygments==2.12.0    # to avoid high-severity issue.
+pygments==2.15.0    # to avoid high-severity issue.
 pyzmq==25.0.0
 qutip==4.7.0
 selenium==4.2.0