Pin td-agent to 4.0.* also on Debian

Debian was missed in the original patch. [1]

Backport to Victoria.

[1] 6d0882e
aka Iefcdd3100b7e3c5320bc5f1286a18251bdeab885

Closes-Bug: #1930867
Change-Id: Id5938697b62ba040062475fcf5215d64e1ba8c6f
(cherry picked from commit 5253e03)

Author: yoctozepto

docker/base/apt_preferences.debian

@@ -17,6 +17,11 @@ Package: erlang*
 Pin: version 1:23.*
 Pin-Priority: 1000
 
+# FIXME(mgoddard): Pinning to 4.0.* to avoid bug 1930867.
+Package: td-agent*
+Pin: version 4.0.*
+Pin-Priority: 1000
+
 # We do not want packages from this repo
 Package: *
 Pin: release o=obs://private/home:marcin.juszkiewicz/debian-buster

releasenotes/notes/bug-1930867-debian-c01f2cd22d8c10f0.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes an issue with logs going missing in the Fluentd pipeline
+    by pinning td-agent to 4.0.* also on Debian.
+    `LP#1930867 [Debian] <https://launchpad.net/bugs/1930867>`__