qt6-base-fourier: fix epoch-mismatch in xcb-private-headers dep

`package_qt6-xcb-private-headers-fourier()` depended on
`qt6-base-fourier=$pkgver` (= literal "6.11.1"), but the package itself
ships with `epoch=1` so the installed version is `1:6.11.1-1`.

Pacman's strict-equality version compare treats "6.11.1" as epoch=0 and
"1:6.11.1" as epoch=1 — mismatch — and refuses every upgrade involving
qt6-xcb-private-headers-fourier with "unable to satisfy dependency".

Fix: include the epoch prefix in the dep string —
`qt6-base-fourier=$epoch:$pkgver`. pkgrel bumped to 2 so the rebuild
publishes a new package even though only the dep string changed.

Observed on ohm 2026-05-18 after the broader fleet pacman -Syu —
worked around there with --assume-installed; this fixes it properly.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

arch/qt6-base-fourier/PKGBUILD

@@ -28,7 +28,7 @@ pkgname=(qt6-base-fourier
          qt6-xcb-private-headers-fourier)
 _pkgver=6.11.1
 pkgver=${_pkgver/-/}
-pkgrel=1
+pkgrel=2
 epoch=1
 arch=(aarch64 x86_64)
 url='https://www.qt.io'
@@ -188,7 +188,7 @@ package_qt6-xcb-private-headers-fourier() {
   conflicts=(qt6-xcb-private-headers)
   replaces=(qt6-xcb-private-headers)
 
-  depends=("qt6-base-fourier=$pkgver")
+  depends=("qt6-base-fourier=$epoch:$pkgver")
   optdepends=()
   groups=()