chore(docs): update Go to v1.25.6

[cuixq]

There are vulnerabilities reported by OSV-Scanner.

+-------------------------------------+------+-----------+----------+---------+---------------+-----------------------------------------+
| OSV URL                             | CVSS | ECOSYSTEM | PACKAGE  | VERSION | FIXED VERSION | SOURCE                                  |
+-------------------------------------+------+-----------+----------+---------+---------------+-----------------------------------------+
| https://osv.dev/GO-2026-4340        |      | Go        | stdlib   | 1.25.5  | 1.25.6        | docs/go.mod                             |
| https://osv.dev/GO-2026-4341        |      | Go        | stdlib   | 1.25.5  | 1.25.6        | docs/go.mod                             |
| https://osv.dev/GO-2026-4342        |      | Go        | stdlib   | 1.25.5  | 1.25.6        | docs/go.mod                             |

[gemini-code-assist]

Warning

You have reached your daily quota limit. Please wait up to 24 hours and I will start processing your requests again!

[gemini-code-assist]

Warning

You have reached your daily quota limit. Please wait up to 24 hours and I will start processing your requests again!