✨ Add docs and tests for Python 3.9 and Python 3.10 (#3712)

Co-authored-by: Thomas Grainger <tagrain@gmail.com>

docs/en/docs/tutorial/query-params.md

@@ -63,27 +63,38 @@ The parameter values in your function will be:
 
 The same way, you can declare optional query parameters, by setting their default to `None`:
 
-```Python hl_lines="9"
-{!../../../docs_src/query_params/tutorial002.py!}
-```
+=== "Python 3.6 and above"
+
+    ```Python hl_lines="9"
+    {!> ../../../docs_src/query_params/tutorial002.py!}
+    ```
+
+=== "Python 3.10 and above"
+
+    ```Python hl_lines="7"
+    {!> ../../../docs_src/query_params/tutorial002_py310.py!}
+    ```
 
 In this case, the function parameter `q` will be optional, and will be `None` by default.
 
 !!! check
     Also notice that **FastAPI** is smart enough to notice that the path parameter `item_id` is a path parameter and `q` is not, so, it's a query parameter.
 
-!!! note
-    FastAPI will know that `q` is optional because of the `= None`.
-
-    The `Optional` in `Optional[str]` is not used by FastAPI (FastAPI will only use the `str` part), but the `Optional[str]` will let your editor help you finding errors in your code.
-
 ## Query parameter type conversion
 
 You can also declare `bool` types, and they will be converted:
 
-```Python hl_lines="9"
-{!../../../docs_src/query_params/tutorial003.py!}
-```
+=== "Python 3.6 and above"
+
+    ```Python hl_lines="9"
+    {!> ../../../docs_src/query_params/tutorial003.py!}
+    ```
+
+=== "Python 3.10 and above"
+
+    ```Python hl_lines="7"
+    {!> ../../../docs_src/query_params/tutorial003_py310.py!}
+    ```
 
 In this case, if you go to:
 
@@ -126,9 +137,17 @@ And you don't have to declare them in any specific order.
 
 They will be detected by name:
 
-```Python hl_lines="8  10"
-{!../../../docs_src/query_params/tutorial004.py!}
-```
+=== "Python 3.6 and above"
+
+    ```Python hl_lines="8  10"
+    {!> ../../../docs_src/query_params/tutorial004.py!}
+    ```
+
+=== "Python 3.10 and above"
+
+    ```Python hl_lines="6  8"
+    {!> ../../../docs_src/query_params/tutorial004_py310.py!}
+    ```
 
 ## Required query parameters
 
@@ -184,9 +203,17 @@ http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
 
 And of course, you can define some parameters as required, some as having a default value, and some entirely optional:
 
-```Python hl_lines="10"
-{!../../../docs_src/query_params/tutorial006.py!}
-```
+=== "Python 3.6 and above"
+
+    ```Python hl_lines="10"
+    {!> ../../../docs_src/query_params/tutorial006.py!}
+    ```
+
+=== "Python 3.10 and above"
+
+    ```Python hl_lines="8"
+    {!> ../../../docs_src/query_params/tutorial006_py310.py!}
+    ```
 
 In this case, there are 3 query parameters: