in-place migrate thrift-py3 [1/2]

Summary:
__Context__: Thrift has two separate but complementary efforts underway to facilitate thrift-py3 migration to thrift-python. The in-place migrate option is a *fully interface compatible* evolution of thrift-py3 to remove as much Cython as possible. For more info, see this [post](https://fb.workplace.com/groups/3562416237359961/permalink/4069004626701117/).

__Benefit__: ***2.5x faster build*** An incremental thrift build currently takes 3 minutes total on trunk, dominated by the cxx1-py3-types build, which takes ~2.5 minutes between the cython compiler and the cxx_compile. With these changes, the time is reduced to 1 minute total.

Repro (on D77409225):
```
buck build @//mode/opt //glean/client/py3/example:example
```

Used py3_inplace codemod script to turn on in-place migrate for glean, since it's a relatively isolated build graph, w/r/t thrift_library edges only.

This change requires updating the glean sync codegen to put the option in generated `thrift_library` TARGETS file. Ran the sync script and verified the `thrift_py3_options` is the only thing that changed:
```
./glean/schema/sync
```

#buildall

Reviewed By: pepeiborra

Differential Revision: D77401593

fbshipit-source-id: ad7b821876a6c123570daf516a4172936bbab1b5

Author: ahilger

glean/schema/gen/Glean/Schema/Gen/Thrift.hs

@@ -97,6 +97,7 @@ genTargets slashVn info oncall =
       "\"types_cpp_splits=" <> cppSplits <> "\""
       ] <> "],"
     , "  thrift_py_options = \"utf8strings\","
+    , "  thrift_py3_options = [\"inplace_migrate\"],"
     , "  languages = [" <> Text.intercalate ", " langs <> "],"
     , "  thrift_srcs = { \"" <> namespace <> ".thrift\" : [] },"
     , "  deps = [" <> Text.intercalate ","