action.yml: update dependencies

- actions/checkout: v4.2.2 -> v6.0.1
- actions/setup-go: v5.4.0 -> v6.1.0

See:
- https://github.com/actions/checkout/releases
- https://github.com/actions/setup-go/releases

Notable fixes:
- https://github.com/actions/setup-go/pull/665

Change-Id: I4885641c2e7d15c5362b3aab54c89d7a502ef2be
GitHub-Last-Rev: 81e47c83ae36005a4244b3326362fedbd6e459be
GitHub-Pull-Request: golang/govulncheck-action#8
Reviewed-on: https://go-review.googlesource.com/c/govulncheck-action/+/726120
Auto-Submit: Sean Liao <sean@liao.dev>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
TryBot-Bypass: Sean Liao <sean@liao.dev>
Reviewed-by: Zvonimir Pavlinovic <zpavlinovic@google.com>
Reviewed-by: Sean Liao <sean@liao.dev>

action.yml

diff --git a/action.yml b/action.yml
index 612cd3b..33fe6a6 100644
--- a/action.yml
+++ b/action.yml
@@ -44,8 +44,8 @@
   using: "composite"
   steps:
     - if: inputs.repo-checkout != 'false' # only explicit false prevents repo checkout
-      uses: actions/checkout@v4.2.2
-    - uses: actions/setup-go@v5.4.0
+      uses: actions/checkout@v6.0.2
+    - uses: actions/setup-go@v6.2.0
       with:
         go-version: ${{ inputs.go-version-input }}
         check-latest: ${{ inputs.check-latest }}