Switch back http provider after requests removes LGPL dependency (apa…

…che#16974)

Following merging the psf/requests#5797
and requests 2.26.0 release without LGPL chardet dependency,
we can now bring back http as pre-installed provider as it does
not bring chardet automatically any more.

docs/apache-airflow/extra-packages-ref.rst

@@ -260,7 +260,7 @@ Those are extras that provide support for integration with external systems via
 +---------------------+-----------------------------------------------------+--------------------------------------+--------------+
 | grpc                | ``pip install 'apache-airflow[grpc]'``              | Grpc hooks and operators             |              |
 +---------------------+-----------------------------------------------------+--------------------------------------+--------------+
-| http                | ``pip install 'apache-airflow[http]'``              | HTTP hooks, operators and sensors    |              |
+| http                | ``pip install 'apache-airflow[http]'``              | HTTP hooks, operators and sensors    |      *       |
 +---------------------+-----------------------------------------------------+--------------------------------------+--------------+
 | imap                | ``pip install 'apache-airflow[imap]'``              | IMAP hooks and sensors               |      *       |
 +---------------------+-----------------------------------------------------+--------------------------------------+--------------+

setup.py

@@ -231,13 +231,13 @@ def write_version(filename: str = os.path.join(*[my_dir, "airflow", "git_version
     'distributed>=2.11.1, <2.20',
 ]
 databricks = [
-    'requests>=2.20.0, <3',
+    'requests>=2.26.0, <3',
 ]
 datadog = [
     'datadog>=0.14.0',
 ]
 deprecated_api = [
-    'requests>=2.20.0',
+    'requests>=2.26.0',
 ]
 doc = [
     # Sphinx is limited to < 3.5.0 because of https://github.com/sphinx-doc/sphinx/issues/8880
@@ -333,7 +333,9 @@ def write_version(filename: str = os.path.join(*[my_dir, "airflow", "git_version
     'thrift>=0.9.2',
 ]
 http = [
-    'requests>=2.20.0',
+    # The 2.26.0 release of requests got rid of the chardet LGPL mandatory dependency, allowing us to
+    # release it as a requirement for airflow
+    'requests>=2.26.0',
 ]
 http_provider = [
     # NOTE ! The HTTP provider is NOT preinstalled by default when Airflow is installed - because it
@@ -815,12 +817,9 @@ def sort_extras_requirements() -> Dict[str, List[str]]:
 # Those providers are pre-installed always when airflow is installed.
 # Those providers do not have dependency on airflow2.0 because that would lead to circular dependencies.
 # This is not a problem for PIP but some tools (pipdeptree) show those as a warning.
-# NOTE ! The HTTP provider is NOT preinstalled by default when Airflow is installed - because it
-#        depends on `requests` library and until `chardet` is mandatory dependency of `requests`
-#        we cannot make it mandatory dependency. See https://github.com/psf/requests/pull/5797
 PREINSTALLED_PROVIDERS = [
     'ftp',
-    # 'http',
+    'http',
     'imap',
     'sqlite',
 ]