[CI] Updated ci.py to use task_build.py

`task_build.sh` was replaced with `task_build.py` in
apache#10359.  This commit updates the
`ci.py` script and the contribution documentation to use
`task_build.py` instead of `task_build.sh`.

docs/contribute/ci.rst

@@ -166,7 +166,7 @@ and help in mounting your current directory.
     # the tvm directory is automatically mounted
     # example: build tvm (note: this will overrwrite build/)
     $ ./tests/scripts/task_config_build_cpu.sh
-    $ ./tests/scripts/task_build.sh build -j32
+    $ ./tests/scripts/task_build.py --build-dir build --num-executors 32
 
 
 Reporting Issues

tests/scripts/ci.py

@@ -238,7 +238,7 @@ def docs(
 
     scripts = extra_setup + [
         config,
-        f"./tests/scripts/task_build.sh build -j{NPROC}",
+        f"./tests/scripts/task_build.py --build-dir build --num-executors {NPROC}",
         "./tests/scripts/task_ci_setup.sh",
         "./tests/scripts/task_python_docs.sh",
     ]