Increase doctest timeout to 300s and time print (#3041)

### What this PR does / why we need it?
Increase doctest timeout to 300s and time print, according to time print
in https://github.com/vllm-project/vllm-ascend/pull/3045 , most of time
consumed in `Graph capturing`, so I think it's fine to increase doctest
timeout

This PR also add time log for each task.

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

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

- vLLM version: v0.10.2
- vLLM main:
a684c0124c

Closes: https://github.com/vllm-project/vllm-ascend/issues/3045

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

tests/e2e/doctests/001-quickstart-test.sh

@@ -57,8 +57,8 @@ function quickstart_online_test() {
 }
 
 _info "====> Start simple_test"
-simple_test
+time simple_test
 _info "====> Start quickstart_offline_test"
-quickstart_offline_test
+time quickstart_offline_test
 _info "====> Start quickstart_online_test"
-quickstart_online_test
+time quickstart_online_test

tests/e2e/doctests/002-pip-binary-installation-test.sh

@@ -59,4 +59,4 @@ function install_binary_test() {
 }
 
 _info "====> Start install_binary_test"
-install_binary_test
+time install_binary_test