ci(gosec): use go.mod for Go version + add manual trigger (#1634)

Author: libotony

.github/workflows/gosec.yaml

@@ -1,5 +1,6 @@
 name: Gosec
 on:
+  workflow_dispatch:
   schedule:
   #   # This is meant to run every day at 8am
     - cron:  '0 8 * * 1-5'
@@ -19,7 +20,7 @@ jobs:
         uses: actions/checkout@v5
       - uses: actions/setup-go@v5
         with:
-          go-version: '1.26.x'
+          go-version-file: 'go.mod'
           cache: false
       - name: Run Gosec
         id: gosec-run