Pin npm autoprefixer package for site generation

[markmandel]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespace from that line:

/kind breaking

/kind bug

/kind cleanup
/kind documentation
/kind feature
/kind hotfix

What this PR does / Why we need it:

The 10.0.0 release of autoprefixer broke site generation, so pinning the version to a 9.x.x release.

Which issue(s) this PR fixes:

N/A

Special notes for your reviewer:

This will unclog CI as well.

[roberthbailey]

At some point this is going to come back and bite us if we forget to ever check to see if they fix things (or figure out how to upgrade to post 10.0.0) but this seems like a reasonable short term fix. Can you open a tracking bug to get back onto a non-pinned version in the future?

[markmandel]

Should we create a ticket to update this dependency -- or should the ticket be to upgrade hugo+docsy, and therefore the whole suite of dependencies?

(I expect at some point Hugo/Docsy will work out how to work with the new version)

[roberthbailey]

Either way is fine, just as long as we don't stay pinned forever and forget about it.

[google-oss-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aLekSer, markmandel, roberthbailey

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• OWNERS [aLekSer,markmandel,roberthbailey]

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[agones-bot]

Build Succeeded 👏

Build Id: ec2e55da-7959-4ff2-b67c-77cb5a6bf28e

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.9.0-339c004
• image: gcr.io/agones-images/agones-sdk:1.9.0-339c004
• image: gcr.io/agones-images/agones-ping:1.9.0-339c004
• Linux C++ SDK (build): agonessdk-1.9.0-339c004-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.9.0-339c004.zip

A preview of the website (the last 30 builds are retained):

• https://339c004-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/1818/head:pr_1818 && git checkout pr_1818
• helm install ./install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.9.0-339c004