build: Copy modules.txt to vendor/modules.txt using build commands instead of file modules

Author: pojntfx

com.pojtinger.felicitas.Multiplex.json

@@ -20,14 +20,14 @@
       "name": "app",
       "buildsystem": "simple",
       "build-commands": [
+        "mkdir -p vendor && cp modules.txt vendor/modules.txt",
         ". /usr/lib/sdk/golang/enable.sh && export GOBIN=\"/app/bin\" && go generate ./... && go install -v -mod=vendor .",
         "desktop-file-install --dir=/app/share/applications $FLATPAK_ID.desktop",
         "install -D -m 0644 $FLATPAK_ID.metainfo.xml /app/share/metainfo/$FLATPAK_ID.metainfo.xml",
         "for icon in 16x16 22x22 24x24 32x32 36x36 48x48 64x64 72x72 96x96 128x128 192x192 256x256 512x512; do install -D -m 0644 docs/icon-${icon}.png /app/share/icons/hicolor/${icon}/apps/$FLATPAK_ID.png; done"
       ],
       "sources": [
         { "type": "dir", "path": "." },
-        { "type": "file", "path": "modules.txt", "dest": "vendor" },
         {
           "type": "archive",
           "url": "https://proxy.golang.org/github.com/anacrolix/torrent/@v/v1.52.5.zip",