fix: upgrade Go toolchain to 1.25.8 to resolve stdlib vulnerabilities (#717)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: dlevy-msft-sql <[email protected]>

Author: Copilot

.github/workflows/security.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v6
         with:
-          go-version: '1.25.7'
+          go-version: '1.25.8'
 
       - name: Install govulncheck
         run: go install golang.org/x/vuln/cmd/govulncheck@latest

go.mod

@@ -1,6 +1,6 @@
 module github.com/microsoft/go-sqlcmd
 
-go 1.25.7
+go 1.25.8
 
 require (
 	github.com/alecthomas/chroma/v2 v2.23.1