ikiwiki/ news/ version 3.20250501

ikiwiki 3.20250501 released with these changes

- [ Antoine Beaupré ]

  - adjust logo from black to mid-point grey so it contrasts equally well on a black background to a white one.

- [ Jonathan Dowland ]

  - po4a: attempt to detect versions ≥ 0.70 and continue to support earlier versions (for now), such that modern ikiwiki can be built and operate on Debian stable (bookworm).
  - actiontabs: add support for dark mode