Fix typos mostly in comments, docs and test names (GH-15209)

diff --git a/Python/ast.c b/Python/ast.c
index 8b3dbea..1152402 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -5356,7 +5356,7 @@
        doubling the number allocated each time. Note that the f-string
        f'{0}a{1}' contains 3 expr_ty's: 2 FormattedValue's, and one
        Constant for the literal 'a'. So you add expr_ty's about twice as
-       fast as you add exressions in an f-string. */
+       fast as you add expressions in an f-string. */
 
     Py_ssize_t allocated;  /* Number we've allocated. */
     Py_ssize_t size;       /* Number we've used. */
diff --git a/Python/pystate.c b/Python/pystate.c
index 3b2adf5..dc52400 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -729,7 +729,7 @@
         return -1;
     }
     if (state->modules_by_index == NULL) {
-        Py_FatalError("PyState_RemoveModule: Interpreters module-list not acessible.");
+        Py_FatalError("PyState_RemoveModule: Interpreters module-list not accessible.");
         return -1;
     }
     if (index > PyList_GET_SIZE(state->modules_by_index)) {
@@ -888,7 +888,7 @@
  * Note that, if there is a current thread state, it *must* be the one
  * passed as argument.  Also, this won't touch any other interpreters
  * than the current one, since we don't know which thread state should
- * be kept in those other interpreteres.
+ * be kept in those other interpreters.
  */
 void
 _PyThreadState_DeleteExcept(_PyRuntimeState *runtime, PyThreadState *tstate)