[ci] adjust .github/workflows/meson.yml

remove typo'd NetBSD image which repeated vmactions/openbsd-vm@v1
NetBSD image vmactions/netbsd-vm@v1 contains some package conflicts
  between NetBSD 9.0 and 9.3, so remove NetBSD from workflow for now.
  (NetBSD might later be added back with cmake or autoconf builds.)

.github/workflows/meson.yml

@@ -100,22 +100,6 @@ jobs:
             meson compile -C "${{github.workspace}}/build" --verbose
             meson test -C "${{github.workspace}}/build" --verbose
 
-  NetBSD:
-    runs-on: ubuntu-latest
-    name: NetBSD
-    steps:
-      - uses: actions/checkout@v4
-      - name: NetBSD
-        uses: vmactions/openbsd-vm@v1
-        with:
-          prepare: |
-            pkg_add ninja meson pkgconf pcre2 perl5
-          run: |
-            meson setup "${{github.workspace}}/build" -Dwarning_level=3
-            meson compile -C "${{github.workspace}}/build" --verbose
-            # TODO: figure out why tests/lighttpd.conf not found; works for FreeBSD and DragonFly
-            #meson test -C "${{github.workspace}}/build" --verbose
-
   OpenBSD:
     runs-on: ubuntu-latest
     name: OpenBSD