Fix SourceHut package CI dependencies

ober

8c24579c0553cf1841e3ae34bc59534a03130752

diff --git a/.build.yml b/.build.yml
index 889f377..e867394 100644
--- a/.build.yml
+++ b/.build.yml
@@ -6,6 +6,7 @@ packages:
   - zlib1g-dev
   - liblz4-dev
   - libx11-dev
+  - file
   - git
   - curl
   - unzip