Drop python 3.7 (and 2.7) for recipes under dev-python/

Recipes with only 3.7 are left alone. Help with #8025.

dev-python/sqlalchemy/sqlalchemy-1.3.22.recipe

@@ -8,7 +8,7 @@ simple and Pythonic domain language."
 HOMEPAGE="https://www.sqlalchemy.org/"
 COPYRIGHT="2006-2019 SQLAlchemy authors and contributors"
 LICENSE="MIT"
-REVISION="3"
+REVISION="4"
 SOURCE_URI="https://pypi.org/packages/source/S/SQLAlchemy/SQLAlchemy-$portVersion.tar.gz"
 CHECKSUM_SHA256="758fc8c4d6c0336e617f9f6919f9daea3ab6bb9b07005eda9a1a682e24a6cacc"
 SOURCE_DIR="SQLAlchemy-$portVersion"
@@ -30,8 +30,8 @@ BUILD_PREREQUIRES="
 	gcc$secondaryArchSuffix
 	"
 
-PYTHON_PACKAGES=(python3 python38 python39 python310)
-PYTHON_VERSIONS=(3.7 3.8 3.9 3.10)
+PYTHON_PACKAGES=(python38 python39 python310)
+PYTHON_VERSIONS=(3.8 3.9 3.10)
 for i in "${!PYTHON_PACKAGES[@]}"; do
 pythonPackage=${PYTHON_PACKAGES[i]}
 pythonVersion=${PYTHON_VERSIONS[$i]}
@@ -50,9 +50,6 @@ BUILD_PREREQUIRES="$BUILD_PREREQUIRES
 done
 
 if [ "$targetArchitecture" = "x86_gcc2" ]; then
-	PROVIDES_python3+="
-		sqlalchemy_python3 = $portVersion
-		"
 	PROVIDES_python38+="
 		sqlalchemy_python38 = $portVersion
 		"