Remove experimental warning and enable -W (#1468)

* remove warning

* release note

qiskit_ibm_runtime/__init__.py

@@ -184,5 +184,3 @@
 """The environment variable name that is used to set the level for the IBM Quantum logger."""
 QISKIT_IBM_RUNTIME_LOG_FILE = "QISKIT_IBM_RUNTIME_LOG_FILE"
 """The environment variable name that is used to set the file for the IBM Quantum logger."""
-
-warnings.warn("You are using the experimental-0.2 branch. Stability is not guaranteed.")

releasenotes/notes/v2-primitives-ada671f4df7caa39.yaml

@@ -0,0 +1,14 @@
+---
+features:
+  - |
+    This release add a version 2 of the primitives -
+    :class:`~qiskit_ibm_runtime.SamplerV2` and
+    :class:`~qiskit_ibm_runtime.EstimatorV2`.
+    The emphasis of this new version is on performing vectorized calls to the
+    primitive ``run()`` methods, so that sweeps over parameter value sets and
+    observables can be efficiently specified.  The sampler has also been
+    changed to return the outputs (e.g. bitstrings) from every shot,
+    rather than providing a counts-like return.
+    See the
+    `Migration Guide <https://docs.quantum.ibm.com/api/migration-guides/v2-primitives>`_
+    for more details on the changes and migration steps.

tox.ini

@@ -40,7 +40,7 @@ envdir = .tox/docs
 deps =
   -r requirements-dev.txt
 commands =
-  sphinx-build -j auto -b html {posargs} {toxinidir}/docs {toxinidir}/docs/_build/html
+  sphinx-build -j auto -W -b html {posargs} {toxinidir}/docs {toxinidir}/docs/_build/html
 
 [testenv:docs-clean]
 skip_install = true