Fix python3.8 support

Python 3.8 and 3.9 use outdated syntax.
Ideally this commit should be reverted on 3.8 and 3.9 support drop.

Resolves: #5

src/pycountries/languages.py

@@ -40,7 +40,7 @@ class LanguageUnitBase(BaseModel):
     )
 
 
-if sys.version_info >= (3, 9):  # noqa: UP036
+if sys.version_info >= (3, 10):  # noqa: UP036
 
     class LanguageUnit(LanguageUnitBase):
         alpha_2: str | None = Field(

src/pycountries/phones.py

@@ -19,14 +19,15 @@ class PhoneUnitBase(BaseModel):
     calling_code: int = Field(
         description="International calling code",
     )
+    # prefixes: list[int]  # Abstract property
 
     def is_prefix_supported(self, prefix: int, /) -> bool:
         if not self.prefixes or prefix is None:
             return True
         return prefix in self.prefixes
 
 
-if sys.version_info >= (3, 9):  # noqa: UP036
+if sys.version_info >= (3, 10):  # noqa: UP036
 
     class PhoneUnit(PhoneUnitBase):
         prefixes: list[int]