Bump Go toolchain to v1.23.8

[mboersma]

/kind cleanup

What this PR does / why we need it:

Updates the Go toolchain to v1.23.8.

In the past, CAPZ bumped the Go version along with the CAPI minor version. But I extracted this change from #5533 because several other PRs seem to need the updated compiler, and it doesn't seem problematic to bump the Go version ahead of the CAPI version. Go v1.22 is also no longer receiving updates.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

TODOs:

• squashed commits
• includes documentation
• adds unit tests
• cherry-pick candidate

Release note:

NONE

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 52.86%. Comparing base (d5b47bf) to head (4ab62ae).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5561   +/-   ##
=======================================
  Coverage   52.86%   52.86%           
=======================================
  Files         272      272           
  Lines       29474    29474           
=======================================
  Hits        15582    15582           
  Misses      13080    13080           
  Partials      812      812           

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[mboersma]

/retest

[nawazkh]

I don't know if the netlify failures are expected here.

2:47:38 PM: + /tmp/gen-crd-api-reference-docs-642c3aa7441d324f54f5a9a6a1841ffffacf5aeb/gen-crd-api-reference-docs -config /tmp/gen-crd-api-reference-docs-642c3aa7441d324f54f5a9a6a1841ffffacf5aeb/example-config.json -template-dir /tmp/gen-crd-api-reference-docs-642c3aa7441d324f54f5a9a6a1841ffffacf5aeb/template -api-dir ./api/v1beta1 -out-file ./docs/book/src/reference/v1beta1-api-raw.html
2:47:38 PM: I0410 21:47:38.659517   10752 main.go:144] parsing go packages in directory ./api/v1beta1
2:47:44 PM: I0410 21:47:44.161926   10752 main.go:222] found 1 packages
2:47:48 PM: F0410 21:47:48.564433   10752 main.go:150] no API packages found in ./api/v1beta1
2:47:48 PM: ​
2:47:48 PM: "build.command" failed                                        
2:47:48 PM: ────────────────────────────────────────────────────────────────
2:47:48 PM: ​
2:47:48 PM:   Error message
2:47:48 PM:   Command failed with exit code 255: ./docs/book/install-and-build.sh (https://ntl.fyi/exit-code-255)
2:47:48 PM: ​
2:47:48 PM:   Error location
2:47:48 PM:   In build.command from netlify.toml:
2:47:48 PM:   ./docs/book/install-and-build.sh
2:47:48 PM: ​
2:47:48 PM:   Resolved config
2:47:48 PM:   build:
2:47:48 PM:     command: ./docs/book/install-and-build.sh
2:47:48 PM:     commandOrigin: config
2:47:48 PM:     environment:
2:47:48 PM:       - REVIEW_ID
2:47:48 PM:     publish: /opt/build/repo/docs/book/bookout
2:47:48 PM:     publishOrigin: config
2:47:48 PM:   redirects:
2:47:48 PM:     - force: true
2:47:48 PM:       from: https://master--kubernetes-sigs-cluster-api-provider-azure.netlify.com/*
2:47:48 PM:       status: 301
2:47:48 PM:       to: https://master.cluster-api-provider-azure.sigs.k8s.io/:splat
2:47:48 PM:     - force: true
2:47:48 PM:       from: http://master.cluster-api-provider-azure.sigs.k8s.io/*
2:47:48 PM:       status: 301
2:47:48 PM:       to: https://master.cluster-api-provider-azure.sigs.k8s.io/:splat
2:47:48 PM:     - force: true
2:47:48 PM:       from: http://master--kubernetes-sigs-cluster-api-provider-azure.netlify.com/*
2:47:48 PM:       status: 301
2:47:48 PM:       to: http://master.cluster-api-provider-azure.sigs.k8s.io/:splat
2:47:48 PM:   redirectsOrigin: config
2:47:49 PM: Failed during stage 'building site': Build script returned non-zero exit code: 2 (https://ntl.fyi/exit-code-2)
2:47:49 PM: Build failed due to a user error: Build script returned non-zero exit code: 2
2:47:49 PM: Failing build: Failed to build site
2:47:49 PM: Finished processing build request in 1m0.854s
9:51:27 AM: [ERROR] Deploy logs are currently unavailable. We are working on resolving the issue.

Running ./docs/book/install-and-build.sh locally on a copy of this PR yields the same error.
I wonder if we also have to update the versions for the below in docs/book/install-and-build.sh ?

mdBookVersion="v0.4.40"
genCRDAPIReferenceDocsVersion="642c3aa7441d324f54f5a9a6a1841ffffacf5aeb"

[mboersma]

make -C docs/book build started failing sometime recently, so Netlify deploy is failing on (almost) all PRs. Nothing to do with this change.

I can reproduce the problem locally, but haven't found a fix yet.

I did try updating mdbook to the most recent version v0.4.48, but no joy.

[mboersma]

It's really a separate tool used to generate CRD documentation that's failing here AFAICT: gen-crd-api-reference-docs from a now-unsupported GitHub repo. :-| I'll make a separate issue for this.

Edit: see #5564

[nawazkh]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: nawazkh

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[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 3d37511868badcf77eaa74a28f7f74b3859535cd

[mboersma]

I think #5565 will unblock this.

[nawazkh]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: fb40e6172a409b1c03d98503aa04b895947b5049

[nojnhuh]

Note for anyone who might be looking here when updating Go to the next version: it probably doesn't hurt to also bump the image used in cloudbuild.yaml like in #5715. The complete list of available tags can be found with this command:

curl https://gcr.io/v2/k8s-staging-test-infra/gcb-docker-gcloud/tags/list | jq .tags

Then to figure out the go version:

docker run --rm --entrypoint go gcr.io/k8s-staging-test-infra/gcb-docker-gcloud:v20250116-2a05ea7e3d version

Obviously not critical that this stays up to date since we hadn't updated for four years, but probably a good idea not to push the limit.