A couple more loose-egs flag flips

Namely inside,
- `ActorNursery.open_portal()` which uses
  `.trionics.maybe_open_nursery()` and is now adjusted to
  pass-through `**kwargs` for at least this flag.
- inside the `.trionics.gather_contexts()`.

tractor/_portal.py

@@ -533,6 +533,10 @@ async def open_portal(
     async with maybe_open_nursery(
         tn,
         shield=shield,
+        strict_exception_groups=False,
+        # ^XXX^ TODO? soo roll our own then ??
+        # -> since we kinda want the "if only one `.exception` then
+        # just raise that" interface?
     ) as tn:
 
         if not channel.connected():

tractor/trionics/_broadcast.py

@@ -15,7 +15,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 '''
-``tokio`` style broadcast channel.
+`tokio` style broadcast channel.
 https://docs.rs/tokio/1.11.0/tokio/sync/broadcast/index.html
 
 '''

tractor/trionics/_mngrs.py

@@ -57,6 +57,8 @@ async def maybe_open_nursery(
     shield: bool = False,
     lib: ModuleType = trio,
 
+    **kwargs,  # proxy thru
+
 ) -> AsyncGenerator[trio.Nursery, Any]:
     '''
     Create a new nursery if None provided.
@@ -67,7 +69,7 @@ async def maybe_open_nursery(
     if nursery is not None:
         yield nursery
     else:
-        async with lib.open_nursery() as nursery:
+        async with lib.open_nursery(**kwargs) as nursery:
             nursery.cancel_scope.shield = shield
             yield nursery
 
@@ -143,9 +145,14 @@ async def gather_contexts(
             'Use a non-lazy iterator or sequence type intead!'
         )
 
-    async with trio.open_nursery() as n:
+    async with trio.open_nursery(
+        strict_exception_groups=False,
+        # ^XXX^ TODO? soo roll our own then ??
+        # -> since we kinda want the "if only one `.exception` then
+        # just raise that" interface?
+    ) as tn:
         for mngr in mngrs:
-            n.start_soon(
+            tn.start_soon(
                 _enter_and_wait,
                 mngr,
                 unwrapped,