chore(python): bump idna from 3.4 to 3.7 in .kokoro (#1953)

build(deps): bump idna

Bumps [idna](https://github.com/kjd/idna) from 3.4 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v3.4...v3.7)

---
updated-dependencies:
- dependency-name: idna
  dependency-type: indirect
...

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

Author: dependabot[bot]

synthtool/gcp/templates/python_library/.kokoro/requirements.txt

@@ -252,9 +252,9 @@ googleapis-common-protos==1.61.0 \
     --hash=sha256:22f1915393bb3245343f6efe87f6fe868532efc12aa26b391b15132e1279f1c0 \
     --hash=sha256:8a64866a97f6304a7179873a465d6eee97b7a24ec6cfd78e0f575e96b821240b
     # via google-api-core
-idna==3.4 \
-    --hash=sha256:814f528e8dead7d329833b91c5faa87d60bf71824cd12a7530b5526063d02cb4 \
-    --hash=sha256:90b77e79eaa3eba6de819a0c442c0b4ceefc341a7a2ab77d7562bf49f425c5c2
+idna==3.7 \
+    --hash=sha256:028ff3aadf0609c1fd278d8ea3089299412a7a8b9bd005dd08b9f8285bcb5cfc \
+    --hash=sha256:82fee1fc78add43492d3a1898bfa6d8a904cc97d8427f683ed8e798d07761aa0
     # via requests
 importlib-metadata==6.8.0 \
     --hash=sha256:3ebb78df84a805d7698245025b975d9d67053cd94c79245ba4b3eb694abe68bb \