(chore): bump go to 1.18

[grokspawn]

Description of the change:
bump go to 1.18

Motivation for the change:

Reviewer Checklist

• Implementation matches the proposed design, or proposal is updated to match implementation
• Sufficient unit test coverage
• Sufficient end-to-end test coverage
• Docs updated or added to /docs
• Commit messages sensible and descriptive

[codecov]

Codecov Report

Merging #971 (80e4a13) into master (043db4f) will not change coverage.
The diff coverage is 0.00%.

❗ Current head 80e4a13 differs from pull request most recent head 9c6bc23. Consider uploading reports for the commit 9c6bc23 to get more accurate results

@@           Coverage Diff           @@
##           master     #971   +/-   ##
=======================================
  Coverage   52.48%   52.48%           
=======================================
  Files         103      103           
  Lines        9240     9240           
=======================================
  Hits         4850     4850           
  Misses       3468     3468           
  Partials      922      922           

Impacted Files	Coverage Δ
pkg/api/registry.pb.go	3.06% <ø> (ø)
pkg/api/registry_grpc.pb.go	0.00% <0.00%> (ø)

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[timflannagan]

/lgtm

[njhale]

Looks like some empty files -- see pkg/lib/indexer/index.Dockerfile* -- were included. I suspect they're generated by a local test. Can we drop them, or are they intentional?

@grokspawn

[timflannagan]

/lgtm

[njhale]

Nice 👍

/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: grokspawn, njhale, timflannagan

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[openshift-bot]

/retest-required

Please review the full test history for this PR and help us cut down flakes.