fix(gooddata-api-client): restore null-byte regex pattern dropped by OpenAPI Generator

OpenAPI Generator v6.6.0 silently drops the \x00 literal from regex
patterns in the generated Python code.  The DeclarativeColumn model's
`name` field has a spec pattern of `^[^\x00]*$` (reject null bytes,
important for Postgres TEXT columns), but the generator produced the
invalid Python regex `^[^]*$`, causing `re.PatternError: unterminated
character set` at runtime.

Fix the generated file and add a post-generation sed fixup to the
Makefile `api-client` target so future regenerations are patched
automatically.

jira: TRIVIAL
risk: low

Author: hkad98

Makefile

@@ -58,6 +58,11 @@ api-client: download
 	rm -f schemas/gooddata-api-client.json
 	cat schemas/gooddata-*.json | jq -S -s 'reduce .[] as $$item ({}; . * $$item) + { tags : ( reduce .[].tags as $$item (null; . + $$item) | unique_by(.name) ) }' | sed '/\u0000/d' > "schemas/gooddata-api-client.json"
 	$(call generate_client,api)
+	# OpenAPI Generator drops the \x00 literal from regex patterns like ^[^\x00]*$,
+	# producing the invalid Python regex ^[^]*$.  Restore the null-byte escape.
+	find gooddata-api-client/gooddata_api_client -name '*.py' -exec \
+		sed -i.bak 's/\^\[\^\]\*\$$/^[^\\x00]*$$/g' {} + && \
+		find gooddata-api-client/gooddata_api_client -name '*.py.bak' -delete
 
 .PHONY: download
 download:

gooddata-api-client/gooddata_api_client/model/declarative_column.py

@@ -71,7 +71,7 @@ class DeclarativeColumn(ModelNormal):
         ('name',): {
             'max_length': 255,
             'regex': {
-                'pattern': r'^[^]*$',  # noqa: E501
+                'pattern': r'^[^\x00]*$',  # noqa: E501
             },
         },
         ('description',): {