chore(python): remove .gitignore from templates (#1608)

* chore(python): remove .gitignore from templates

Source-Link: googleapis/synthtool@419d94c
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:a7aef70df5f13313ddc027409fc8f3151422ec2a57ac8730fce8fa75c060d5bb

* Remove replacement in owlbot.py

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Anthonios Partheniou <[email protected]>

Author: gcf-owl-bot[bot]

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:5581906b957284864632cde4e9c51d1cc66b0094990b27e689132fe5cd036046
-# created: 2025-01-16T15:24:11.364245182Z
+  digest: sha256:a7aef70df5f13313ddc027409fc8f3151422ec2a57ac8730fce8fa75c060d5bb
+# created: 2025-04-10T17:00:10.042601326Z

owlbot.py

@@ -64,13 +64,6 @@
 # Fixup files
 # ----------------------------------------------------------------------------
 
-# Add scratch space for experimentation to .gitignore.
-assert 1 == s.replace(
-    [".gitignore"],
-    re.escape("# Make sure a generated file isn't accidentally committed.\n"),
-    "# Make sure a generated file isn't accidentally committed.\ndemo.ipynb\n",
-)
-
 # Encourage sharring all relevant versions in bug reports.
 assert 1 == s.replace(  # bug_report.md
     [".github/ISSUE_TEMPLATE/bug_report.md"],