[buildbot] docker: buildworker: add missing file package

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch main:
https://git.openwrt.org/cd6a70c93310d44a5fd01177be6c4640ba3f5e9b

commit cd6a70c93310d44a5fd01177be6c4640ba3f5e9b
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Fri Sep 27 07:33:09 2024 +0000

    docker: buildworker: add missing file package
    
    In Debian 11 (Bullseye), the `file` package was installed indirectly
    because the `man-db` package recommended it. The `man-db` package is
    often installed as a dependency of other packages, such as
    `build-essential` and tools like `gcc` and `make`.  By default,
    `apt-get` installs recommended packages, so `file` was installed
    automatically.
    
    Starting from Debian 12 (Bookworm), the `man-db` package no longer
    recommends the `file` package. This change was made to reduce the size
    of minimal container images and installations where `file` is not
    essential.
    
    So lets install this package explicitly.
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 docker/buildworker/Dockerfile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docker/buildworker/Dockerfile b/docker/buildworker/Dockerfile
index 28a30db..b7cf36a 100644
--- a/docker/buildworker/Dockerfile
+++ b/docker/buildworker/Dockerfile
@@ -17,6 +17,7 @@ RUN \
 		build-essential \
 		ccache \
 		curl \
+		file \
 		gawk \
 		g++-multilib \
 		gcc-multilib \