main/boot-deploy: upgrade to 0.15 (MR 5044)

Features:
  - Include "sort-key" in bootloader spec config (MR 58)
  - Integrate pmos-update-depthcharge-kernel and pmos-update kernel
    logic (MR 55)

[ci:skip-build] already built successfully in CI

main/boot-deploy/APKBUILD

 # Maintainer: Clayton Craft <clayton@craftyguy.net>
 pkgname=boot-deploy
-pkgver=0.14
+pkgver=0.15
 pkgrel=0
 pkgdesc="tool for finalizing and deploying boot related files"
 url="https://gitlab.com/postmarketos/boot-deploy"
@@ -28,5 +28,5 @@ package() {
 }
 sha512sums="
 a243975b9850d9933e0f917f7eb38fc4a76ea658c3dcc56f035f60ee6c62d6740c1107143b8210bdc0231d4c9b6b2003e458120985604eb09649322d359ae89f  os-customization
-6db023dadd7edf2836b23b2404cff0ea2ba6ad373008b0c43dfe31a62d4b9b17e9f981f6ccadb30330030ef491f0f492a5baed2d395eb277a6b1790bd3541dfd  boot-deploy-0.14.tar.gz
+b0d41a9c6fd3608fd8b5dec7dc8538605bff629a67fd6608fcb7dc79e6c92cec732ebea5551bba88f8530001f05a15347e3f9c4ad017ccec8485db9d1fa8364a  boot-deploy-0.15.tar.gz
 "