add sbt-protobuf in artifact-migrations.conf

[xuwei-k]

• use sbt-ci-release. change groupId sbt/sbt-protobuf#74
• https://repo1.maven.org/maven2/com/github/sbt/sbt-protobuf_2.12_1.0/

[codecov]

Codecov Report

Merging #1986 (f9ed896) into master (b5e60eb) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1986   +/-   ##
=======================================
  Coverage   78.52%   78.52%           
=======================================
  Files         130      130           
  Lines        2244     2244           
  Branches       53       53           
=======================================
  Hits         1762     1762           
  Misses        482      482           

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