[CI] enable custom ops build (#466)

### What this PR does / why we need it?
This PR enable custom ops build  by default. 

### Does this PR introduce _any_ user-facing change?

Yes, users now install vllm-ascend from source will trigger custom ops
build step.

### How was this patch tested?
By image build and e2e CI

---------

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

docs/source/quick_start.md

@@ -9,7 +9,7 @@
 ## Setup environment using container
 
 :::::{tab-set}
-::::{tab-item} Ubuntu OS
+::::{tab-item} Ubuntu
 
 ```{code-block} bash
    :substitutions:
@@ -35,7 +35,7 @@ docker run --rm \
 ```
 ::::
 
-::::{tab-item} openEuler OS
+::::{tab-item} openEuler
 
 ```{code-block} bash
    :substitutions: