chore(4.0.x): release 4.0.5

[release-please]

🤖 I have created a release *beep* *boop*

4.0.5 (2021-12-17)

Dependencies

• 4.0.x: bump OpenCensus API to 0.30.0 (#1601) (fe9c7cc)

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[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (4.0.x@fe9c7cc). Click here to learn what that means.
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@@           Coverage Diff            @@
##             4.0.x    #1619   +/-   ##
========================================
  Coverage         ?   85.22%           
  Complexity       ?     2623           
========================================
  Files            ?      145           
  Lines            ?    14292           
  Branches         ?     1380           
========================================
  Hits             ?    12181           
  Misses           ?     1534           
  Partials         ?      577           

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[release-please]

🤖 Release is at https://github.com/googleapis/java-spanner/releases/tag/v4.0.5 🌻

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