Add wget to Nix flake devShell

We use wget to download sources of some projects analysed in
experiments.

RPM: make python3-setuptools a runtime dependency

snapshot.py imports pkg_resources to include information about the used
DiffKemp version in the snapshot. We have seen some failures when using
DiffKemp RPM of kind:

    $ diffkemp build ...
    Traceback (most recent call last):
      File "/usr/bin/diffkemp", line 3, in <module>
        from diffkemp import diffkemp
      File "/usr/lib64/python3.11/site-packages/diffkemp/diffkemp.py", line 3, in <module>
        from diffkemp.config import Config
      File "/usr/lib64/python3.11/site-packages/diffkemp/config.py", line 3, in <module>
        from diffkemp.snapshot import Snapshot
      File "/usr/lib64/python3.11/site-packages/diffkemp/snapshot.py", line 14, in <module>
        import pkg_resources
    ModuleNotFoundError: No module named 'pkg_resources'

Since pkg_resources is a part of setuptools, make python3-setuptools a
runtime dependency.

RPM: add forgotten build dependency for viewer

Release version 0.4.0

Changelog:
- Reworked CLI interface (generate split into multiple commands)
- New command for analysing any Makefile-based projects
- Support for LLVM 14 and 15
- SimpLL used as a library by default
- Support for custom patterns
- Handling code relocations
- Improved handling of inverse branching conditions
- Prevent analysing snapshots with other LLVM version

Fixes for LLVM 13

RPM spec: add python3-setuptools to BuildRequires

Version 0.2.2

Version 0.2.1

Version 0.2.0

Version 0.1.1