CODEOWNERS: change out_stackdriver code owners

Due to some changes in the team, we have decided to adjust the
codeowners for the `out_stackdriver` plugin. Since @lingshi and
@igorpeshansky have transitioned to new teams not involved with the
plugin, we have decided to remove them from CODEOWNERS so they don't
need to deal with the context switching it would require. In their place
we are adding @jefferbrecht, who has been working with Fluent Bit around
as long as I have and has lots of necessary context to be able to review
out_stackdriver PRs. We are hoping to add more in the future.

Signed-off-by: braydonk <[email protected]>

CODEOWNERS

@@ -63,7 +63,7 @@
 /plugins/out_datadog     @nokute78 @edsiper
 /plugins/out_es          @pettitwesley @edsiper
 /plugins/out_pgsql       @sxd
-/plugins/out_stackdriver @braydonk @igorpeshansky @qingling128
+/plugins/out_stackdriver @braydonk @jefferbrecht @jeffluoo
 
 # AWS Plugins
 /plugins/out_s3               @pettitwesley
@@ -85,8 +85,8 @@
 
 # Google test code
 # --------------
-/tests/runtime/out_stackdriver.c @braydonk @igorpeshansky @qingling128
-/tests/runtime/data/stackdriver  @braydonk @igorpeshansky @qingling128
+/tests/runtime/out_stackdriver.c @braydonk @jefferbrecht @jeffluoo
+/tests/runtime/data/stackdriver  @braydonk @jefferbrecht @jeffluoo
 
 # Devcontainer
 /.devcontainer                  @patrick-stephens @niedbalski @edsiper