main/postmarketos-initramfs: fix filesystem detection

Changes the regex of the initramfs to make sure that it is searching for filesystem type instead of any type (e.g. partition scheme type).

Currently while trying to find the filesystem type of a partition the regex of the initramfs can instead get fed the partition scheme type (e.g. gpt), causing it to error with an unsupported filesystem error.

Fixes #3303 (closed)

main/postmarketos-initramfs/APKBUILD

 # Maintainer: Caleb Connolly <caleb@postmarketos.org>
 # Co-Maintainer: Clayton Craft <clayton@craftyguy.net>
 pkgname=postmarketos-initramfs
-pkgver=3.4.4
+pkgver=3.4.5
 pkgrel=0
 pkgdesc="Base files for the postmarketOS initramfs / initramfs-extra"
 url="https://postmarketos.org"
@@ -106,7 +106,7 @@ sha512sums="
 c0233d22858a5901db64e1d2fe1f6d39a2e2cfd1b94a10932483f55fed9461e9b8aa2d73b154b9d99a7a8b49ee02abfbddfe917ce0c6d7576601ba2668589c01  00-initramfs-base.files
 d0f35562365756d93066ce45924d17fb347b54095179c3262daa2f073e12743505cd5d9372ad30485915ca754d95a8edba9a74314e7949e0b3cf6978a87d03a5  00-initramfs-extra-base.files
 966284e8ef8f840258a84019db4a6ddd436cdc50193e0673532f70fef86a6e4c1bfd21b682f3708251b6b670ca569c90016926d0926babc5a0257bb33ae55d79  init.sh
-eab20e07a632f814a1b36426a7b4087ac9195c9ed7cb22fb0b386b93a5be07c0b1a677e228d7bf3ff8e6d5e4307596848f743aec25d138d1a6625b3d885e0454  init_functions.sh
+522e3e52921ad7e9ab689f37888ac439583bab2ee73455508262fbcbe06a85a8f3be753518f2706c5d20bb56ae28587cd61ac23e6602a7f17758147d4b6e3fe0  init_functions.sh
 18a0ca97bca094aeb8cb1c2582205ac0aff131085c39f1715246541cacfb35434aba515cd5d338703843efb36b9effd494a51361c51fb39be6052ad866346d3d  init_2nd.sh
 30fb52456376020e70116169752582d25a011a858111a347c2e53eccaddea8765fab502371cfdc0c2a8ca93034795b7e689e4cd3393ad601268c02024c4e84ab  init_functions_2nd.sh
 675e7d5bee39b2df7d322117f8dcaccc274d61beaf4d50ead19bbf2109446d64b1c0aa0c5b4f9846eb6c1c403418f28f6364eff4537ba41120fbfcbc484b7da7  mdev.conf