{finagle, finatra, util, twitter-server, scrooge}: Drop scala 2.11 fo…

…r OSS

Problem/Solution:
Two scala versions (2.12, 2.13) is sufficient.
Let's drop scala 2.11.

JIRA Issues: CSL-10599

Differential Revision: https://phabricator.twitter.biz/D631091

.github/workflows/continuous-integration.yml

@@ -19,9 +19,6 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # We don't run the 2.11.x series with finagle because the build matrix becomes
-        # too large. GitHub limits the build matrix to 256.
-        # https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix
         scala: [2.12.8, 2.13.1]
         java: ['1.8', '1.11']
         project: ['finagle-base-http', 'finagle-benchmark', 'finagle-benchmark-thrift', 'finagle-core', 'finagle-example', 'finagle-exception', 'finagle-exp', 'finagle-grpc-context', 'finagle-http', 'finagle-http2','finagle-init','finagle-integration','finagle-memcached','finagle-mux','finagle-mysql','finagle-netty4','finagle-netty4-http','finagle-opencensus-tracing','finagle-partitioning','finagle-redis','finagle-scribe','finagle-serversets','finagle-stats','finagle-stats-core','finagle-thrift','finagle-thriftmux','finagle-toggle','finagle-tunable','finagle-zipkin-core','finagle-zipkin-scribe']
@@ -74,9 +71,6 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # We don't run the 2.11.x series with finagle because the build matrix becomes
-        # too large. GitHub limits the build matrix to 256.
-        # https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix
         scala: [2.12.8, 2.13.1]
         java: ['1.8', '1.11']
         project: ['finagle-base-http','finagle-core','finagle-http','finagle-http2','finagle-integration','finagle-mux','finagle-mysql','finagle-netty4','finagle-netty4-http','finagle-thriftmux']

CHANGELOG.rst

@@ -21,6 +21,7 @@ New Features
 
 Breaking API Changes
 ~~~~~~~~~~~~~~~~~~~~
+* finagle: Builds are now only supported for Scala 2.12+ ``PHAB_ID=D631091``
 
 * finagle-core: Changed flag `-com.twitter.finagle.loadbalancer.exp.apertureEagerConnections"
   from having Boolean values true or false to `EagerConnectionsType` values `Enable`,

build.sbt

@@ -139,7 +139,7 @@ val sharedSettings = Seq(
   version := releaseVersion,
   organization := "com.twitter",
   scalaVersion := "2.12.11",
-  crossScalaVersions := Seq("2.11.12", "2.12.11", "2.13.1"),
+  crossScalaVersions := Seq("2.12.11", "2.13.1"),
   fork in Test := true, // We have to fork to get the JavaOptions
   libraryDependencies ++= Seq(
     // See https://www.scala-sbt.org/0.13/docs/Testing.html#JUnit