Remove the specified isolated_server from the builder() callers.

Follow up of https://crrev.com/c/2400058

Bug: 894045
Change-Id: Id5837c7d742c060f1e2b7e969a7d337b193676f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2400578
Auto-Submit: Ye Kuang <yekuang@google.com>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805250}

infra/config/lib/ci.star

@@ -474,7 +474,6 @@ def ci_builder(
             bq_table = "luci-resultdb.chromium.ci_test_results",
         )],
         notifies = notifies,
-        isolated_server = "https://isolateserver.appspot.com",
         **kwargs
     )
 

infra/config/lib/try.star

@@ -242,7 +242,6 @@ def try_builder(
         resultdb_bigquery_exports = [resultdb.export_test_results(
             bq_table = "luci-resultdb.chromium.try_test_results",
         )],
-        isolated_server = "https://isolateserver.appspot.com",
         **kwargs
     )
 

infra/config/subprojects/goma/goma.star

@@ -52,7 +52,6 @@ def fyi_goma_canary_builder(*, name, **kwargs):
         name = name,
         builder_group = "chromium.goma.fyi",
         execution_timeout = 10 * time.hour,
-        isolated_server = "https://isolateserver.appspot.com",
         **kwargs
     )