Fix PR Build Failures Due to Hugo Version Mismatch

[ibrahimjaved12]

What are the relevant tickets?

Closes https://github.com/mitodl/hq/issues/6548

Description (What does it do?)

Hugo's latest version is 0.141.0, whereas:

1. In our codebase, we use 0.112.7.
2. For our PR checks, we use latest version.
   Which means, if latest version has any breaking changes, they would have an effect on our PR checks. Which is why our build is currently failing with the errors:

execute of template failed: template: partials/featured_course_cards.html:27:24: executing "partials/featured_course_cards.html" at <.Err>: can't evaluate field Err in type resource.Resource: Resource.Err was removed in Hugo v0.141.0 and replaced with a new try keyword, see
We could fix them by using try keyword, but we would still have a version mismatch between what we use for production, and what we use for these tests.

Apart from this, there are more breaking changes in the latest version so we would have to incrementally upgrade Hugo to get there.

This PR upgrades Hugo version from 0.112.7 to 0.115.4.

Additional Context - Why 0.115.4?

From 0.115.4 to 0.117.0 it seems there are some internal changes due to which our jest tests became super slow.
FAIL tests-e2e/jest/build-failures.test.ts (24.125 s)

  OCW Build Failures
    ✓ Instructor static API errors crash build (1076 ms)
    ✕ Instructor static API errors crash build (5010 ms)
    ✓ Featured course static API failures (1[13](https://github.com/mitodl/ocw-hugo-themes/actions/runs/12903355910/job/35978461722#step:6:14)6 ms)
    ✕ Featured course static API failures (5017 ms)
    ✓ Featured course static API failures (1898 ms)
    ✕ Featured course static API failures (5017 ms)

The 3 tests fail because of timeout. After removing the timeout, they pass at 152 seconds:

 PASS  tests-e2e/jest/build-failures.test.ts (152.508 s)
  OCW Build Failures
    ✓ Instructor static API errors crash build (2141 ms)
    ✓ Instructor static API errors crash build (84098 ms)
    ✓ Featured course static API failures (1200 ms)
    ✓ Featured course static API failures (30646 ms)
    ✓ Featured course static API failures (1176 ms)
    ✓ Featured course static API failures (30670 ms)

For 0.117.0, the release notes indicate:

• testing: Write test caches to /tmp
• Add retry in resources.GetRemote for temporary HTTP errors

Particularly, the second one seems related, where it adds exponential backoff for retry for HTTP errors. The tests that are taking much longer time actually have 504 in them. From the code in Hugo PR for 0.117.0:
temporaryHTTPCodes := []int{408, 429, 500, 502, 503, 504}

So for now, I'm upgrading to 0.115.4 to fix the breaking build check on our PRs. But I shared the R&D because it may be helpful for next upgrade.

How can this be tested?

Run yarn install
Run yarn start course and yarn start www and make sure everything is working fine.
For detailed testing, you can follow this PR instructions: #1167

[github-actions]

Netlify Deployments:
www: https://ocw-hugo-themes-www-pr-1495--ocw-next.netlify.app/
Course v2: https://ocw-hugo-themes-course-v2-pr-1495--ocw-next.netlify.app/

[github-actions]

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