feat(go.mod): update go-sql-driver/mysql version to v1.8.1

[mayooot]

An error occurs when use k3s server --datastore-endpoint='mysql://root:root@tcp(localhost:3306)/foo%2Fbar' is used to create k3s.

Because the go-sql-driver version used by k3s is earlier than v1.8.0, Refer to README.md.

For more information, loft-sh/vcluster#2152

[lucasfcnunes]

Fixes loft-sh/vcluster#2152.

[lucasfcnunes]

@mayooot You have commits missing the message Signed-off-by: Author Name <authoremail@example.com>. To sign, always commit with git commit -s -m '...'.

To rebase sign the last already committed:

To add your Signed-off-by line to every commit in this branch:
Ensure you have a local copy of your branch by checking out the pull request locally via command line.
In your local branch, run: git rebase HEAD~1 --signoff
Force push your changes to overwrite the branch: git push --force-with-lease origin feat/update-go-sql-driver-version

[mayooot]

@lucasfcnunes thanks a lot!

[brandond]

This module should be bumped on the Kine side first. We can bump this here once that is done.

[brandond]

Closing, will be updated when kine is updated.

[lucasfcnunes]

@brandond seems that we continue to use https://github.com/go-sql-driver/mysql/releases/tag/v1.7.1 on kine and k3s instead of https://github.com/go-sql-driver/mysql/releases/tag/v1.8.0 or higher.