### What this PR does / why we need it?
Add container image build ci:
- Enable branch, tag docker image publish
- branch image: `vllm-ascend:main`, `vllm-ascend:v0.7.1-dev`
- tag image: `vllm-ascend:v0.7.1rc1`
- Enable PR docker image build check
- other changes:
- Prepare the `REPO_OWNER` because the ghcr lowerercase required
- Add `Free up disk space` step to avoid `No space left on device` like
https://github.com/vllm-project/vllm-ascend/issues/27
- Setup qemu with image to resolve
https://github.com/docker/setup-qemu-action/issues/198
### Does this PR introduce _any_ user-facing change?
NO
### How was this patch tested?
build: CI passed [push
false](https://github.com/vllm-project/vllm-ascend/actions/runs/13347017608/job/37278724158?pr=64)
Note for test case:
1. merge commits ot `main`, `v0.7.1-dev` branch
✅ main: https://github.com/Yikun/vllm-ascend/actions/runs/13347238961
--> ghcr.io/yikun/vllm-ascend:main OK
✅v0.7.1-dev:
https://github.com/Yikun/vllm-ascend/actions/runs/13347229912 -->
ghcr.io/yikun/vllm-ascend:v0.7.1-dev OK
2. create pep440 tag from github release: v0.7.1rc1, v0.7.1,
v0.7.1rc1.dev1 all release has latest
✅ v0.7.5 --> v0.7.5, latest
✅ v0.7.5rc1 --> v0.7.5rc1
✅ v0.7.5rc1.dev1 --> v0.7.5rc1.dev1
(no latest, add a todo here) v0.7.5rc1.post1 --> v0.7.5rc1.post1
3. create unknow tag from github release:
✅ create 0.7.1 on v0.7.1-dev: not trigger ( only prefix v triggerd)
4. create tag from git:
✅ also works, `git tag v0.7.99;git push origin v0.7.99` from
publish-image
Signed-off-by: Yikun Jiang <yikunkero@gmail.com>