Bump actions/setup-go from 5.5.0 to 6.4.0

Bumps [actions/setup-go](https://github.com/actions/setup-go) from 5.5.0 to 6.4.0.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](actions/setup-go@d35c59a...4a36011)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-version: 6.4.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
       - name: Install Go
-        uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
           go-version: 1.26.x
       - run: go build -o promu-intermediate
@@ -37,7 +37,7 @@ jobs:
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
       - name: Install Go
-        uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6.4.0
         with:
           go-version: 1.26.x
       - run: go build -o promu-intermediate