Revert "3rdparty: jackson upgrade to 2.13.0"

Problem

2.13.0 introduced a regression, where they were double-serializing.  We're
worried that this will lead to a substantial performance regression. Github
ticket: FasterXML/jackson-databind#3308

Solution

This reverts commit e27353b784543196b9f5fd572110e4b4fe04f4c4.

JIRA Issues: CSL-11459

Differential Revision: https://phabricator.twitter.biz/D780287

CHANGELOG.rst

@@ -36,11 +36,6 @@ Breaking API Changes
 * finagle-core: `c.t.f.loadbalancer.distributor.AddressedFactory` has been removed. Use
 `c.t.f.loadbalancer.EndpointFactory` directly instead. ``PHAB_ID=D751145``
 
-Runtime Behavior Changes
-~~~~~~~~~~~~~~~~~~~~~~~~
-
-* finagle: Bump version of Jackson to 2.13.0. ``PHAB_ID=D744627``
-
 * finagle-core: Moved `c.t.finagle.stats.LoadedStatsReceiver` and `c.t.finagle.stats.DefaultStatsReceiver`
   from the finagle-core module to util-stats.  ``PHAB_ID=D763497``
 

build.sbt

@@ -65,7 +65,7 @@ val netty4LibsTest = Seq(
 val netty4Http = "io.netty" % "netty-codec-http" % netty4Version
 val netty4Http2 = "io.netty" % "netty-codec-http2" % netty4Version
 val opencensusVersion = "0.24.0"
-val jacksonVersion = "2.13.0"
+val jacksonVersion = "2.11.4"
 val jacksonLibs = Seq(
   "com.fasterxml.jackson.core" % "jackson-core" % jacksonVersion,
   "com.fasterxml.jackson.core" % "jackson-databind" % jacksonVersion,