github: use the same headers on yaml files

Also adjust the mention of location of mkosi files,
follow-up for d55ad7fe96.

.github/workflows/labeler.yml

@@ -1,4 +1,8 @@
+---
+# vi: ts=2 sw=2 et:
+#
 name: "Pull Request Labeler"
+
 on:
 - pull_request_target
 

.github/workflows/linter.yml

@@ -1,6 +1,6 @@
 ---
+# vi: ts=2 sw=2 et:
 # https://github.com/marketplace/actions/super-linter
-
 name: Lint Code Base
 
 on:

.github/workflows/mkosi.yml

@@ -1,7 +1,8 @@
+---
+# vi: ts=2 sw=2 et:
+# Simple boot tests that build and boot the mkosi images generated by the mkosi config files in mkosi.default.d/.
 name: mkosi
 
-# Simple boot tests that build and boot the mkosi images generated by the mkosi config files in .mkosi.
-
 on:
   push:
     branches:
@@ -31,7 +32,7 @@ jobs:
       run: sudo apt-get update && sudo apt-get install --no-install-recommends python3-pexpect python3-jinja2
 
     - name: Configure
-      run: echo -e "[Distribution]\nDistribution=${{ matrix.distro }}\n" > mkosi.default
+      run: echo -e "[Distribution]\nDistribution=${{ matrix.distro }}\n" >mkosi.default
 
     # Ubuntu's systemd-nspawn doesn't support faccessat2() syscall, which is
     # required, since current Arch's glibc implements faccessat() via faccessat2().