Fix failing non-cloud functional tests by using built-in caching on t…

…he setup-go action (#8276)

# Description

This PR is to remediate frequent failures of the [scheduled functional
test
(noncloud)](/~https://github.com/radius-project/radius/blob/main/.github/workflows/functional-test-noncloud.yaml)
workflow. We are having issues with the caching logic. A test failure
example is
[here](/~https://github.com/radius-project/radius/actions/runs/12912790930/job/36008466625#step:8:31).

This PR updates the workflow to remove the caching steps from the
workflow and replace it with a new feature of the `actions/setup-go@v5`
action, in which caching of Go dependencies is enabled by setting the
`cache` parameter to `true`. See [the
docs](/~https://github.com/actions/setup-go/blob/main/docs/adrs/0000-caching-dependencies.md)
for details.

I also tested using the `ubuntu-latest` test runner, under the
assumption that the non-cloud tests will have fewer artifact outputs and
not need the larger disk on `ubuntu-latest-m`.

Changes:

*
[`.github/workflows/functional-test-noncloud.yaml`](diffhunk://#diff-b7af1cc5c43a85f1f7d316c6e244726bb14b0b34b59512f60deea7abd498b90cL182-R182):
Enabled caching for Go dependencies by setting the `cache` parameter to
`true` in the `setup-go` action, and removed the manual cache path setup
and cleanup steps to streamline the workflow.
*
[`.github/workflows/functional-test-noncloud.yaml`](diffhunk://#diff-b7af1cc5c43a85f1f7d316c6e244726bb14b0b34b59512f60deea7abd498b90cL129-R129):
Updated the operating system from `ubuntu-latest-m` to `ubuntu-latest`.
Testing for this workflow in a fork did not encounter disk space limits
we have seen on other workflows where we tested `ubuntu-latest`.
 
## Type of change

- This pull request is a minor refactor, code cleanup, test improvement,
or other maintenance task and doesn't change the functionality of Radius
(issue link optional).

Fixes: #8274 

## Contributor checklist
Please verify that the PR meets the following requirements, where
applicable:

- [ ] An overview of proposed schema changes is included in a linked
GitHub issue.
- [ ] A design document PR is created in the [design-notes
repository](/~https://github.com/radius-project/design-notes/), if new
APIs are being introduced.
- [ ] If applicable, design document has been reviewed and approved by
Radius maintainers/approvers.
- [ ] A PR for the [samples
repository](/~https://github.com/radius-project/samples) is created, if
existing samples are affected by the changes in this PR.
- [ ] A PR for the [documentation
repository](/~https://github.com/radius-project/docs) is created, if the
changes in this PR affect the documentation or any user facing updates
are made.
- [ ] A PR for the [recipes
repository](/~https://github.com/radius-project/recipes) is created, if
existing recipes are affected by the changes in this PR.

---------

Signed-off-by: Brooke Hamilton <45323234+brooke-hamilton@users.noreply.github.com>

.github/workflows/functional-test-noncloud.yaml

@@ -126,7 +126,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        os: [ubuntu-latest-m]
+        os: [ubuntu-latest]
         name:
           [
             cli-noncloud,
@@ -179,25 +179,7 @@ jobs:
         uses: actions/setup-go@v5
         with:
           go-version: ${{ env.GOVER }}
-          cache: false
-
-      - name: Get Go Cache path
-        id: go-cache-paths
-        run: |
-          echo "go-build=$(go env GOCACHE)" >> $GITHUB_OUTPUT
-          sudo rm -rf $(go env GOCACHE)
-
-          echo "go-mod=$(go env GOMODCACHE)" >> $GITHUB_OUTPUT
-          sudo rm -rf $(go env GOMODCACHE)
-
-      - uses: actions/cache@v4
-        with:
-          path: |
-            ${{ steps.go-cache-paths.outputs.go-build }}
-            ${{ steps.go-cache-paths.outputs.go-mod }}
-          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-go-
+          cache: true
 
       - name: Setup Node.js
         uses: actions/setup-node@v4