deb,rpm: add kmod as recommended dependency to provide modprobe

Depending on the host configuration, the `br_netfilter` module may not
be loaded by default. In this situation, docker will try to load the module
through `modprobe`.

Older versions of docker would silently ignore failing to do so, log a message,
and continue;

    time="2024-11-29T20:04:58.538404376Z" level=warning msg="Running modprobe bridge br_netfilter failed with message: , error: exec: \"modprobe\": executable file not found in $PATH"

However, starting with [db25b0dcd0461802289e962aa0df3abd323d1994][1] and
[264c15bfc427d1321c5b302e48e16d113b06ef92][2], we now produce an error:

    === FAIL: libnetwork/drivers/bridge TestCreateFullOptions (0.04s)
    time="2024-11-29T19:03:44Z" level=error msg="Running modprobe br_netfilter failed with message: " error="exec: \"modprobe\": executable file not found in $PATH"
        bridge_linux_test.go:280: Failed to create bridge: loadBridgeNetFilterModule failed: cannot restrict inter-container communication: modprobe br_netfilter failed: exec: "modprobe": executable file not found in $PATH

This patch updates the packages to add `kmod` (which provides `modprobe`)
as a recommended dependency. We should probably look for alternatives in
our code to not require `modprobe`.

[1]: moby/moby@db25b0d
[2]: moby/moby@264c15b

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Author: thaJeztah

deb/common/control

@@ -34,6 +34,7 @@ Recommends: apparmor,
             ca-certificates,
             docker-ce-rootless-extras,
             git,
+            kmod,
             libltdl7,
             pigz,
             procps,

rpm/SPECS/docker-ce.spec

@@ -13,6 +13,8 @@ Vendor: Docker
 Packager: Docker <[email protected]>
 
 Requires: /usr/sbin/groupadd
+# Provides modprobe, which we use to load br_netfilter if not loaded.
+Recommends: kmod
 Requires: docker-ce-cli
 Recommends: docker-ce-rootless-extras
 Requires: container-selinux >= 2:2.74