Enable warn as error for libraries (#34457)

This enables warn as error for the libraries jobs now that our builds
are warning free.

Author: jaredpar

eng/pipelines/libraries/base-job.yml

@@ -44,7 +44,6 @@ jobs:
         - _runtimeOSArg: ''
         - _finalFrameworkArg: ''
         - _buildScript: $(_buildScriptFileName)$(scriptExt)
-        - _warnAsErrorArg: ''
         - _testScopeArg: ''
         - _extraHelixArguments: ''
         - _crossBuildPropertyArg: ''
@@ -64,9 +63,6 @@ jobs:
         - ${{ if and(eq(parameters.osGroup, 'Linux'), eq(parameters.osSubGroup, ''), eq(parameters.archType, 'arm')) }}:
           - _runtimeOSArg: /p:RuntimeOS=ubuntu.16.04
 
-        - ${{ if and(or(eq(parameters.osGroup, 'Linux'), eq(parameters.osGroup, 'WebAssembly')), ne(parameters.container, '')) }}:
-          - _warnAsErrorArg: '-warnAsError false'
-
         - ${{ if eq(parameters.osGroup, 'WebAssembly') }}:
           - _runtimeOSArg: -os ${{ parameters.osGroup }}
 
@@ -120,7 +116,7 @@ jobs:
         - ${{ if ne(parameters.osGroup, 'Windows_NT') }}:
           - _buildScript: ./$(_buildScriptFileName)$(scriptExt)
 
-        - _buildArguments: -configuration ${{ parameters.buildConfig }} -ci -arch ${{ parameters.archType }} $(_finalFrameworkArg) $(_testScopeArg) $(_warnAsErrorArg) $(_runtimeOSArg) $(_msbuildCommonParameters) $(_runtimeArtifactsPathArg) $(_crossBuildPropertyArg)
+        - _buildArguments: -configuration ${{ parameters.buildConfig }} -ci -arch ${{ parameters.archType }} $(_finalFrameworkArg) $(_testScopeArg) $(_runtimeOSArg) $(_msbuildCommonParameters) $(_runtimeArtifactsPathArg) $(_crossBuildPropertyArg)
         - ${{ parameters.variables }}
 
       dependsOn: