feat(pkgbuilds): add anaconda dependencies packaging

Add PKGBUILD files for four Anaconda installer dependencies:
- pykickstart: Kickstart language parser (>= 3.73)
- python-blivet: Storage management abstraction layer
- python-productmd: OS product metadata parsers
- python-requests-file: file:// URL transport adapter for requests

These packages are required by rhinstaller but absent from Arch repos and AUR.
All use manual module installation to avoid unnecessary build dependencies.

Also fix .gitignore by removing pkgbuilds/ exclusion to allow tracking these new packages.

pkgbuilds/python-requests-file/PKGBUILD

@@ -0,0 +1,25 @@
+# Maintainer: FWS
+# Dépendance de l'installateur Anaconda (rhinstaller) — adaptateur Requests
+# pour les URL file:// (utilisé par le payload). Absent des dépôts Arch et de
+# l'AUR. Module Python mono-fichier (pyproject : py-modules=["requests_file"]).
+pkgname=python-requests-file
+pkgver=2.1.0
+pkgrel=1
+pkgdesc="Transport adapter for using file:// URLs with python-requests (dépendance Anaconda)"
+arch=('any')
+url="https://github.com/dashea/requests-file"
+license=('Apache-2.0')
+depends=('python' 'python-requests')
+source=("$pkgname-$pkgver.tar.gz::https://github.com/dashea/requests-file/archive/refs/tags/$pkgver.tar.gz")
+sha256sums=('f5bf0a9d5a220b03ded522d0992b9c2778adaa084a8735710ad66f663fd91c6b')
+_srcdir="requests-file-$pkgver"
+
+package() {
+  cd "$srcdir/$_srcdir"
+  local sitedir
+  sitedir=$(python -c 'import site; print(site.getsitepackages()[0])')
+  # Module mono-fichier (pas de package dir) → on installe requests_file.py seul.
+  install -Dm644 requests_file.py "$pkgdir$sitedir/requests_file.py"
+  python -m compileall -q -d "$sitedir" "$pkgdir$sitedir/requests_file.py" || true
+  install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+}