chore(deps): update github actions (googleapis#2563)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/setup-go](https://redirect.github.com/actions/setup-go) |
action | minor | `v6.2.0` → `v6.3.0` |
|
[lycheeverse/lychee-action](https://redirect.github.com/lycheeverse/lychee-action)
([changelog](https://redirect.github.com/lycheeverse/lychee-action/compare/a8c4c7cb88f0c7386610c35eb25108e448569cb0..8646ba30535128ac92d33dfc9133794bfdd9b411))
| action | digest | `a8c4c7c` → `8646ba3` |

---

### Release Notes

<details>
<summary>actions/setup-go (actions/setup-go)</summary>

###
[`v6.3.0`](https://redirect.github.com/actions/setup-go/compare/v6.2.0...v6.3.0)

[Compare
Source](https://redirect.github.com/actions/setup-go/compare/v6.2.0...v6.3.0)

</details>

---

### Configuration

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Automerge - At any time (no schedule defined).

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are satisfied.

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rebase/retry checkbox.

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---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
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---

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View the [repository job
log](https://developer.mend.io/github/googleapis/genai-toolbox).

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Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com>
Co-authored-by: Averi Kitsch <akitsch@google.com>

Author: 3 people

.github/workflows/link_checker.yaml

@@ -64,7 +64,7 @@ jobs:
       - name: Link Checker
         id: lychee-check       
         if: steps.changed-files.outputs.HAS_CHANGES == 'true'
-        uses: lycheeverse/lychee-action@a8c4c7cb88f0c7386610c35eb25108e448569cb0 # v2
+        uses: lycheeverse/lychee-action@8646ba30535128ac92d33dfc9133794bfdd9b411 # v2
         continue-on-error: true 
         with:
           args: >

.github/workflows/link_checker_report.yaml

@@ -29,7 +29,7 @@ jobs:
 
       - name: Link Checker
         id: lychee-check
-        uses: lycheeverse/lychee-action@a8c4c7cb88f0c7386610c35eb25108e448569cb0 # v2
+        uses: lycheeverse/lychee-action@8646ba30535128ac92d33dfc9133794bfdd9b411 # v2
         continue-on-error: true
         with:
           args: >

.github/workflows/lint.yaml

@@ -63,7 +63,7 @@ jobs:
               console.log('Failed to remove label. Another job may have already removed it!');
             }
       - name: Setup Go
-        uses: actions/setup-go@7a3fe6cf4cb3a834922a1244abfce67bcef6a0c5 # v6.2.0
+        uses: actions/setup-go@4b73464bb391d4059bd26b0524d20df3927bd417 # v6.3.0
         with:
           go-version: "1.25"
       - name: Checkout code

.github/workflows/tests.yaml

@@ -75,7 +75,7 @@ jobs:
             }
 
       - name: Setup Go
-        uses: actions/setup-go@7a3fe6cf4cb3a834922a1244abfce67bcef6a0c5 # v6.2.0
+        uses: actions/setup-go@4b73464bb391d4059bd26b0524d20df3927bd417 # v6.3.0
         with:
           go-version: "1.24"