GObject-Introspection fixes

• d/control: Build-depend on dh-sequence-gir

  Without this (or its imperative equivalent, dh --with gir or dh_girepository), ${gir:Depends} and similar substvars won't be populated.

  Closes: #1132395

• d/control: Add ${gir:Depends} to libayatana-ido3-dev instead of hard-coding

  This avoids mistakes, and will make it easier to implement the <!nogir> build-profile at a later date, if desired.

• d/control: Add ${gir:Provides} to -dev package

  This ensures that it will provide the appropriate systematic name derived from its .gir file, and signals that it was not built with GObject-Introspection disabled (which is not currently set up, but could be added later via the nogir build-profile).

• d/control: Explicitly build-depend on gir1.2-gtk-3.0-dev

  This virtual package name can be mechanically derived from the use of --include=Gtk-3.0 in the build system. It ensures that the build-dependencies will be unsatisfiable if GTK was built with the nogir build-profile during bootstrapping.

• d/control: Drop build-dependency on libgirepository1.0-dev

  This transitional package can't be multi-arch/cross-compilation-friendly. Since trixie, a B-D on gobject-introspection (>= 1.80) and the gir1.2-*-dev packages used by this particular package is preferred.

  Closes: #1118788

---

I've confirmed using diffoscope that this produces the same binaries as rebuilding the current source code, except for the following changes to dependency fields etc.:

• Package: gir1.2-ayatanaido3-0.4 Depends: gir1.2-gtk-3.0 (#1132395)
• Package: libayatana-ido3-dev Depends: gir1.2-gtk-3.0-dev and Depends are in a different order
• Package: libayatana-ido3-dev Provides: gir1.2-ayatanaido3-0.4-dev (= 0.10.4-1)
• buildinfo: gir1.2-girepository-2.0, gir1.2-girepository-2.0-dev, libgirepository-1.0-dev, libgirepository1.0-dev are no longer installed (#1118788)