*: improve docker scripts

[xhebox]

Signed-off-by: xhe xw897002528@gmail.com

What problem does this PR solve?

Issue Number: close None

Problem Summary: as title.

What is changed and how it works:

1. shrink docker image size
2. add make docker-release using docker buildx to push multiple-platform iamges
3. continue to improve CI hit things: always fully update cache after merging, only download cache for PRs. It is actually harder than expected to archive the effect.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Notable changes

• Has configuration change
• Has HTTP API interfaces change (Don't forget to add the declarative for API)
• Has tiproxyctl change
• Other user behavior changes

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[djshow832]

What about this?

!**/*.go
!**/*.mod
!**/*.sum

[xhebox]

I think we need Makefile, too. We need to keep adding new source file types into the list. It makes no difference with adding new ignoring file types.