py-flask-sqlalchemy: update to 3.1.1

- drop py38, add py31[2,3] subports
- switch to PyPI

python/py-flask-sqlalchemy/Portfile

@@ -2,13 +2,11 @@
 
 PortSystem          1.0
 PortGroup           python 1.0
-PortGroup           github 1.0
 
-github.setup        pallets flask-sqlalchemy 2.4.4
-# Change github.tarball_from to 'releases' or 'archive' next update
-github.tarball_from tarball
+name                py-flask-sqlalchemy
+version             3.1.1
+revision            0
 
-name                py-${name}
 categories-append   www
 supported_archs     noarch
 platforms           {darwin any}
@@ -22,14 +20,22 @@ long_description    \
     simplify using SQLAlchemy with Flask by providing useful defaults and extra \
     helpers that make it easier to accomplish common tasks.
 
-homepage            https://flask-sqlalchemy.palletsprojects.com/
-checksums           rmd160  5c493b912057c2f461628d1973c166e22587ffef \
-                    sha256  38cb910e652f6a45a8735321211fb6fc70a1a0c9fcb5b84bb2d33bd36929aff7 \
-                    size    131897
+homepage            https://flask-sqlalchemy.readthedocs.io
 
-python.versions     38
+distname            flask_sqlalchemy-${version}
+
+checksums           rmd160  49d159280aebd5dcfe0b53a1ae898867a65d8c1e \
+                    sha256  e4b68bb881802dda1a7d878b2fc84c06d1ee57fb40b874d3dc97dabfa36b8312 \
+                    size    81899
+
+python.versions     312 313
+python.pep517_backend flit
 
 if {${name} ne ${subport}} {
-    depends_lib-append      port:py${python.version}-flask \
-                            port:py${python.version}-sqlalchemy
+    depends_lib-append \
+                    port:py${python.version}-flask \
+                    port:py${python.version}-sqlalchemy
+
+    test.run        yes
+    test.env-append PYTHONPATH=${destroot}${python.pkgd}
 }