Reimplement pythondeps.sh as parametric macro generators

pythondeps.sh was written in shell and unlike the Python dist generators,
it uses no Python, it plainly determines the provide / requires from the path.
As the script was run for every Python file, we were potentially doing hundreds
of shelling outs to execute a script that calls grep and sed.

In Lua, this is much more efficient.

Some timings:
    https://github.com/rpm-software-management/rpm/pull/1153#issuecomment-607146356

Parametric macro generators require RPM 4.16+:
    https://fedoraproject.org/wiki/Changes/RPM-4.16

Fixes https://github.com/rpm-software-management/rpm/issues/1152
Upstream PR: https://github.com/rpm-software-management/rpm/pull/1153

Since this is intended for Fedora 33+ only, clean some old cruft.

python.attr

@@ -1,4 +1,28 @@
-%__python_provides	%{_rpmconfigdir}/pythondeps.sh --provides
-%__python_requires	%{_rpmconfigdir}/pythondeps.sh --requires
+%__python_provides() %{lua:
+    -- Match buildroot/payload paths of the form
+    --    /PATH/OF/BUILDROOT/usr/bin/pythonMAJOR.MINOR
+    -- generating a line of the form
+    --    python(abi) = MAJOR.MINOR
+    -- (Don't match against -config tools e.g. /usr/bin/python2.6-config)
+    local path = rpm.expand('%1')
+    if path:match('/usr/bin/python%d+%.%d+$') then
+        provides = path:gsub('.*/usr/bin/python(%d+%.%d+)', 'python(abi) = %1')
+        print(provides)
+    end
+}
+
+%__python_requires() %{lua:
+    -- Match buildroot paths of the form
+    --    /PATH/OF/BUILDROOT/usr/lib/pythonMAJOR.MINOR/  and
+    --    /PATH/OF/BUILDROOT/usr/lib64/pythonMAJOR.MINOR/
+    -- generating a line of the form:
+    --    python(abi) = MAJOR.MINOR
+    local path = rpm.expand('%1')
+    if path:match('/usr/lib%d*/python%d+%.%d+/.*') then
+        requires = path:gsub('.*/usr/lib%d*/python(%d+%.%d+)/.*', 'python(abi) = %1')
+        print(requires)
+    end
+}
+
 %__python_path	^((/usr/lib(64)?/python[[:digit:]]\\.[[:digit:]]+/.*\\.(py[oc]?|so))|(^%{_bindir}/python[[:digit:]]\\.[[:digit:]]+))$
 %__python_magic		[Pp]ython.*(executable|byte-compiled)