dashboard: remove nonexistent linux-mips builders

These builders haven't existed for a while, and they consume
horizontal space on the build dashboard, pushing more interesting
columns off of the screen at moderate resolutions.

Updates golang/go#31217

Change-Id: Ib7021b699956d01d17e0ea8b213efd07b17d26f7
Reviewed-on: https://go-review.googlesource.com/c/build/+/193017
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/dashboard/builders.go b/dashboard/builders.go
index 23feda9..1327d7d 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -466,56 +466,6 @@
 		ExpectNum:   1,
 		env:         []string{"GOROOT_BOOTSTRAP=/opt/golang/go-solaris-amd64-bootstrap"},
 	},
-	"host-linux-mips": &HostConfig{
-		Notes:       "", // once ran by Brendan Kirby (@MIPSbkirby), imgtec.com; email bounces
-		OwnerGithub: "",
-		IsReverse:   true,
-		ExpectNum:   1,
-		env: []string{
-			"GOROOT_BOOTSTRAP=/usr/local/go-bootstrap-mips",
-			"GOARCH=mips",
-			"GOHOSTARCH=mips",
-			"GO_TEST_TIMEOUT_SCALE=4",
-		},
-		ReverseAliases: []string{"linux-mips"},
-	},
-	"host-linux-mipsle": &HostConfig{
-		Notes:       "", // once ran by Brendan Kirby (@MIPSbkirby), imgtec.com; email bounces
-		OwnerGithub: "",
-		IsReverse:   true,
-		ExpectNum:   1,
-		env: []string{
-			"GOROOT_BOOTSTRAP=/usr/local/go-bootstrap-mipsle",
-			"GOARCH=mipsle",
-			"GOHOSTARCH=mipsle",
-		},
-		ReverseAliases: []string{"linux-mipsle"},
-	},
-	"host-linux-mips64": &HostConfig{
-		Notes:       "", // once ran by Brendan Kirby (@MIPSbkirby), imgtec.com; email bounces
-		OwnerGithub: "",
-		IsReverse:   true,
-		ExpectNum:   1,
-		env: []string{
-			"GOROOT_BOOTSTRAP=/usr/local/go-bootstrap-mips64",
-			"GOARCH=mips64",
-			"GOHOSTARCH=mips64",
-			"GO_TEST_TIMEOUT_SCALE=4",
-		},
-		ReverseAliases: []string{"linux-mips64"},
-	},
-	"host-linux-mips64le": &HostConfig{
-		Notes:       "", // once ran by Brendan Kirby (@MIPSbkirby), imgtec.com; email bounces
-		OwnerGithub: "",
-		IsReverse:   true,
-		ExpectNum:   1,
-		env: []string{
-			"GOROOT_BOOTSTRAP=/usr/local/go-bootstrap-mips64le",
-			"GOARCH=mips64le",
-			"GOHOSTARCH=mips64le",
-		},
-		ReverseAliases: []string{"linux-mips64le"},
-	},
 	"host-darwin-amd64-zenly-ios": &HostConfig{
 		Notes:       "MacBook Pro hosted by Zenly, running the ios reverse buildlet",
 		OwnerGithub: "znly",
@@ -2086,26 +2036,6 @@
 		FlakyNet: true, // maybe not flaky, but here conservatively
 	})
 	addBuilder(BuildConfig{
-		Name:         "linux-mips",
-		HostType:     "host-linux-mips",
-		SkipSnapshot: true,
-	})
-	addBuilder(BuildConfig{
-		Name:         "linux-mipsle",
-		HostType:     "host-linux-mipsle",
-		SkipSnapshot: true,
-	})
-	addBuilder(BuildConfig{
-		Name:         "linux-mips64",
-		HostType:     "host-linux-mips64",
-		SkipSnapshot: true,
-	})
-	addBuilder(BuildConfig{
-		Name:         "linux-mips64le",
-		HostType:     "host-linux-mips64le",
-		SkipSnapshot: true,
-	})
-	addBuilder(BuildConfig{
 		Name:           "linux-s390x-ibm",
 		HostType:       "host-linux-s390x",
 		numTestHelpers: 0,