fix: downgrade dep for compatability (#5996)

It seems like the latest version of github.com/google/martian/v3
is having issues playing nice with Go 1.15. I downgraded the dep
back to where it was and froze it with renovate.

Fixes: #5984
Fixes: #5927
Fixes: #5926

.github/renovate.json

@@ -12,7 +12,8 @@
     "commitMessageAction": "update",
     "groupName": "all",
     "ignoreDeps": [
-        "google.golang.org/genproto"
+        "google.golang.org/genproto",
+        "github.com/google/martian/v3"
     ],
     "ignorePaths": [
         "**/snippets/**"

go.mod

@@ -7,7 +7,7 @@ require (
 	cloud.google.com/go/storage v1.22.0
 	github.com/golang/protobuf v1.5.2
 	github.com/google/go-cmp v0.5.7
-	github.com/google/martian/v3 v3.3.2
+	github.com/google/martian/v3 v3.2.1
 	github.com/googleapis/gax-go/v2 v2.3.0
 	go.opencensus.io v0.23.0
 	golang.org/x/oauth2 v0.0.0-20220411215720-9780585627b5

go.sum

@@ -143,9 +143,8 @@ github.com/google/martian v2.1.0+incompatible h1:/CP5g8u/VJHijgedC/Legn3BAbAaWPg
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
 github.com/google/martian/v3 v3.0.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
 github.com/google/martian/v3 v3.1.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
+github.com/google/martian/v3 v3.2.1 h1:d8MncMlErDFTwQGBK1xhv026j9kqhvw1Qv9IbWT1VLQ=
 github.com/google/martian/v3 v3.2.1/go.mod h1:oBOf6HBosgwRXnUGWUB05QECsc6uvmMiJ3+6W4l/CUk=
-github.com/google/martian/v3 v3.3.2 h1:IqNFLAmvJOgVlpdEBiQbDc2EwKW77amAycfTuWKdfvw=
-github.com/google/martian/v3 v3.3.2/go.mod h1:oBOf6HBosgwRXnUGWUB05QECsc6uvmMiJ3+6W4l/CUk=
 github.com/google/pprof v0.0.0-20181206194817-3ea8567a2e57/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
 github.com/google/pprof v0.0.0-20190515194954-54271f7e092f/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
 github.com/google/pprof v0.0.0-20191218002539-d4f498aebedc/go.mod h1:ZgVRPoUq/hfqzAqh7sHMqb3I9Rq5C59dIz2SbBwJ4eM=