internal/migration: stop running linux-…-{bullseye,bookworm} builders

These builders have long since been migrated to LUCI, but they had two
different names in the old infrastructure and not all were stopped yet.

We don't have an exact counterpart to linux-amd64-bookworm in LUCI,
but we do have the linux/arm64 builder running on Bookworm there.
There doesn't seem to be enough benefit to justify continuing to run
the old one, so stop it, and we can trivially re-add it in LUCI if it's
deemed worthwhile.

For golang/go#67761.

Change-Id: I984ff8a702efbb6861e624781796411973b6b3e8
Reviewed-on: https://go-review.googlesource.com/c/build/+/666376
Reviewed-by: Michael Pratt <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: dmitshur

internal/migration/migration.go

@@ -36,13 +36,14 @@ var BuildersPortedToLUCI = map[string]bool{
 	"darwin-arm64-12":       true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-darwin-arm64_12.
 
 	// Linux builders (just those covering first-class ports).
-	"linux-386":                     true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386.
-	"linux-386-longtest":            true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386-longtest.
-	"linux-386-clang":               true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386-clang15 (a newer clang, but we won't be adding exactly -clang7 to LUCI by now).
-	"linux-386-sid":                 true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386_debiansid.
-	"linux-386-softfloat":           true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386-softfloat.
-	"linux-arm-aws":                 true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-arm.
-	"linux-amd64":                   true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-amd64.
+	"linux-386": true, "linux-386-bullseye": true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386.
+	"linux-386-longtest":  true,                               // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386-longtest.
+	"linux-386-clang":     true,                               // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386-clang15 (a newer clang, but we won't be adding exactly -clang7 to LUCI by now).
+	"linux-386-sid":       true,                               // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386_debiansid.
+	"linux-386-softfloat": true,                               // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-386-softfloat.
+	"linux-arm-aws":       true,                               // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-arm.
+	"linux-amd64":         true, "linux-amd64-bullseye": true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-amd64.
+	"linux-amd64-bookworm":          true, // Available (in a GOARCH=arm64 variant) as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-arm64.
 	"linux-amd64-longtest":          true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-amd64-longtest.
 	"linux-amd64-perf":              true, // Available in the form of multiple linux-amd64_…-perf_vs_… LUCI builders.
 	"linux-amd64-race":              true, // Available as https://ci.chromium.org/p/golang/builders/ci/gotip-linux-amd64-race.