main/postmarketos-base: move os-release to /usr/lib (MR 5550)

From https://www.man7.org/linux/man-pages/man5/os-release.5.html:

        /usr/lib/os-release is the recommended place to store OS release
        information as of vendor trees. /etc/os-release should be a
        relative symlink to /usr/lib/os-release, to provide
        compatibility with applications only looking at /etc/. A
        relative symlink instead of an symlink is necessary to avoid
        breaking the link in a chroot initrd environment such as dracut.
[ci:skip-build]: already built successfully in CI

main/postmarketos-base/APKBUILD

 pkgname=postmarketos-base
-pkgver=33
+pkgver=34
 pkgrel=0
 pkgdesc="Meta package for minimal postmarketOS base"
 url="https://postmarketos.org"
@@ -53,7 +53,7 @@ _source644="
 	etc/fstab
 	etc/issue
 	etc/motd
-	etc/os-release
+	usr/lib/os-release
 	etc/sysctl.d/disable-rp-filter.conf
 	lib/udev/rules.d/20-tm2-touchkey-input.rules
 	lib/udev/rules.d/20-tm2-touchkey-leds.rules
@@ -99,6 +99,10 @@ package() {
 	for i in $_source755; do
 		install -Dm755 "$srcdir/$(flatpath "$i")" "$pkgdir/$i"
 	done
+
+	# /etc/os-release should be a relative symlink, see:
+	# https://www.man7.org/linux/man-pages/man5/os-release.5.html
+	ln -s ../usr/lib/os-release "$pkgdir"/etc/os-release
 }
 
 mesa() {
@@ -164,7 +168,7 @@ e4576c58c35f80bedddb1e89e186f37d31a186d3e9eb046581b8c5d7b7d435e18924539e851d3e67
 9b8d0493bb64457fe176fea801e0771d3c5279302c61559824bf81b3d2b66d2c1e076f4aaac65f55389005acb18c27e44bed858c2bdbad37d74199f07c86c354  rootfs-etc-fstab
 45bd0742a64a9d3c4a88e152b97edcf3fa1edca28884f9ea69e7c4c365f1e41ef9056dbe204545de7d4b2ba92e1e5872b2a929c2dcc1dd468e627cc3f090b8e6  rootfs-etc-issue
 01403df3b5a2be0dd70387a3c32cf24a77bc097679fbefca585082a0970b7d756723c33687be3809351b5e31c85947db84861118bfeced8f5f865fe2452555ec  rootfs-etc-motd
-093c201f0c7aa203df447f2a8c27e5834520a7016ce2934ddc35fb037d2ec9acf0f7df7c06e07ad24ba7b4d94ef21fe7ff848c58bd62277eeeb08659fbddf1e9  rootfs-etc-os-release
+093c201f0c7aa203df447f2a8c27e5834520a7016ce2934ddc35fb037d2ec9acf0f7df7c06e07ad24ba7b4d94ef21fe7ff848c58bd62277eeeb08659fbddf1e9  rootfs-usr-lib-os-release
 b70ee1b39b5f33c9a3e6bf4259158519691c82c8cefb700d4df49eb749a2cce208082e00d4905b9eea2c4f75b6da62f73931931c92157b4132adb35dcf0e0a6f  rootfs-etc-sysctl.d-disable-rp-filter.conf
 b61c6116f972df08f460494cf3b511b7cb4046a65bb3bd840cddb5ca98518c4514dc5f8a9330bc9ac630e5adbfecc839cbd21f70cac5000a30fd2daeab0f02d7  rootfs-lib-udev-rules.d-20-tm2-touchkey-input.rules
 de4d8f258cb2ce654be15abe0188caa6ca9cc163fd45350f2025e7e9d043878e3f1202ef9033b1b15d7e18c4b40c3b19db387ee050a3baf03c4bd4293f4721e3  rootfs-lib-udev-rules.d-20-tm2-touchkey-leds.rules