IFC-2536: Update generate return types to inject typename into schema

[solababs]

Why

infrahubctl generate return-types fails with a TypeError when the schema contains interface or union types. The root cause is in ariadne-codegen: it automatically injects __typename when generating models for abstract-typed fields, then looks up __typename in schema.type_map. Since __typename is a built-in meta-field and not a schema-defined field, the lookup misses and the codegen fallback tries to create a new GraphQLScalarType("String") — which raises TypeError because "String" is a reserved built-in scalar name in graphql-core.

This makes generate return-types unusable for any Infrahub schema that uses interfaces (which most real schemas do).

What changed

• Behavioral: infrahubctl generate return-types now succeeds on schemas with interface or union types. Previously it raised TypeError: Duplicate type "String".

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

@@                Coverage Diff                @@
##           infrahub-develop     #997   +/-   ##
=================================================
  Coverage             81.43%   81.44%           
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  Files                   134      134           
  Lines                 11359    11365    +6     
  Branches               1703     1705    +2     
=================================================
+ Hits                   9250     9256    +6     
  Misses                 1566     1566           
  Partials                543      543           

Flag	Coverage Δ
integration-tests	41.89% <28.57%> (-0.02%)	⬇️
python-3.10	54.42% <100.00%> (+<0.01%)	⬆️
python-3.11	54.43% <100.00%> (+0.02%)	⬆️
python-3.12	54.43% <100.00%> (+0.04%)	⬆️
python-3.13	54.43% <100.00%> (+0.02%)	⬆️
python-3.14	54.43% <100.00%> (+0.04%)	⬆️
python-filler-3.12	22.71% <0.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
infrahub_sdk/ctl/graphql.py	89.21% <100.00%> (+0.67%)	⬆️

... and 1 file with indirect coverage changes

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[ogenstad]

Good find! Is this a bug that should be reported to ariadne-codegen? I'm wondering if it might be fixed in a later version since the one we've pinned is a bit old.

Could be worth to upgrade to see if it resolves the issue, other than that based on the added code can we have some test that would fail if we removed this inject_typename?