chore: update copyright headers to Istari SPDX format (#305)

## Summary
- Update SPDX copyright headers in `retry.py` and `test_retry.py` from
`© 2025` to `© 2025-2026`
- Update `api.proto` SPDX header from email format to year-range format
(`© 2017-2026 Istari Digital, Inc.`)
- Remove `<dgraph-admin@istaridigital.com>` email from `__maintainer__`
and `__author__` module metadata across 21 Python files

Aligns pydgraph copyright headers with the format established in
dgraph4j PR #284.

**Stacked on top of #304** to incorporate the trivy v0.68.2 → v0.69.3
fix so CI code checks don't fail. (the old release was removed from
GitHub).

## Test plan
- [x] Verify no files contain old `<dgraph-admin@istaridigital.com>`
email in copyright headers
- [x] Verify all SPDX headers use year-range format
- [ ] CI passes (no functional changes)

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: mlwelles

.trunk/trunk.yaml

@@ -63,8 +63,7 @@ lint:
         - name: check-merge-conflict
           enabled: true
   enabled:
-    - trivy@0.68.2
-    - trivy@0.58.2
+    - trivy@0.69.3
     - renovate@42.64.0
     - actionlint@1.7.9
     - bandit@1.9.2

examples/simple/uv.lock

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: © Istari Digital, Inc. <dgraph-admin@istaridigital.com>
+ * SPDX-FileCopyrightText: © 2017-2026 Istari Digital, Inc.
  * SPDX-License-Identifier: Apache-2.0
  */
 

pydgraph/proto/api.proto

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: © 2025 Istari Digital, Inc.
+# SPDX-FileCopyrightText: © 2025-2026 Istari Digital, Inc.
 # SPDX-License-Identifier: Apache-2.0
 
 """Transaction retry utilities for handling Dgraph transaction conflicts.

pydgraph/retry.py

@@ -18,7 +18,7 @@
 from . import helper
 
 __author__ = "Animesh Pathak <animesh@dgrpah.io>"
-__maintainer__ = "Istari Digital <contact@istaridigital.com>"
+__maintainer__ = "Istari Digital, Inc. <dgraph-admin@istaridigital.com>"
 
 
 class ACLTestBase(helper.ClientIntegrationTestCase):

tests/test_acl.py

@@ -6,7 +6,7 @@
 from __future__ import annotations
 
 __author__ = "Garvit Pahal"
-__maintainer__ = "Istari Digital, Inc. "
+__maintainer__ = "Istari Digital, Inc. <dgraph-admin@istaridigital.com>"
 
 import unittest
 

tests/test_client.py

@@ -3,7 +3,7 @@
 
 from __future__ import annotations
 
-__author__ = "Istari Digital, Inc. <dgraph-admin@istaridigital.com>"
+__author__ = "Istari Digital, Inc."
 __maintainer__ = "Istari Digital, Inc. <dgraph-admin@istaridigital.com>"
 
 import logging

tests/test_namespace.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: © 2025 Istari Digital, Inc.
+# SPDX-FileCopyrightText: © 2025-2026 Istari Digital, Inc.
 # SPDX-License-Identifier: Apache-2.0
 
 """Tests for transaction retry utilities."""

tests/test_retry.py

@@ -12,7 +12,7 @@
 from tests import helper
 
 __author__ = "Animesh Pathak <animesh@dgrpah.io>"
-__maintainer__ = "Istari Digital <contact@istaridigital.com>"
+__maintainer__ = "Istari Digital, Inc. <dgraph-admin@istaridigital.com>"
 
 
 class TestTypeSystem(helper.ClientIntegrationTestCase):

tests/test_type_system.py

@@ -14,7 +14,7 @@
 from . import helper
 
 __author__ = "Animesh Pathak <animesh@dgrpah.io>"
-__maintainer__ = "Istari Digital <contact@istaridigital.com>"
+__maintainer__ = "Istari Digital, Inc. <dgraph-admin@istaridigital.com>"
 
 
 class TestUpsertBlock(helper.ClientIntegrationTestCase):