[TEST][DOC] Fix doctest and add system package installation (#1375)

### What this PR does / why we need it?
- Fix
[doctest](https://github.com/vllm-project/vllm-ascend/actions/workflows/vllm_ascend_doctest.yaml?query=event%3Aschedule)
- add system package installation
- Add doc for run doctests
- Cleanup all extra steps in .github/workflows/vllm_ascend_doctest.yaml
- Change schedule job from 4 ---> 12 hours

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
- doctest CI passed
- Local test with
`/vllm-workspace/vllm-ascend/tests/e2e/run_doctests.sh`.

Signed-off-by: Yikun Jiang <yikunkero@gmail.com>

docs/source/quick_start.md

@@ -32,6 +32,8 @@ docker run --rm \
 -v /root/.cache:/root/.cache \
 -p 8000:8000 \
 -it $IMAGE bash
+# Install curl
+apt-get update -y && apt-get install -y curl
 ```
 ::::
 
@@ -58,6 +60,8 @@ docker run --rm \
 -v /root/.cache:/root/.cache \
 -p 8000:8000 \
 -it $IMAGE bash
+# Install curl
+yum update -y && yum install -y curl
 ```
 ::::
 :::::