build(deps): bump idna from 3.4 to 3.7 in /taskcluster

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>

taskcluster/requirements.txt

@@ -283,9 +283,9 @@ giturlparse==0.10.0 \
     --hash=sha256:04ba1a3a099c3093fa8d24a422913c6a9b2c2cd22bcffc939cf72e3e98f672d7 \
     --hash=sha256:2595ab291d30717cda8474b874c9fd509f1b9802ad7f6968c36a45e4b13eb337
     # via mozilla-repo-urls
-idna==3.4 \
-    --hash=sha256:814f528e8dead7d329833b91c5faa87d60bf71824cd12a7530b5526063d02cb4 \
-    --hash=sha256:90b77e79eaa3eba6de819a0c442c0b4ceefc341a7a2ab77d7562bf49f425c5c2
+idna==3.7 \
+    --hash=sha256:028ff3aadf0609c1fd278d8ea3089299412a7a8b9bd005dd08b9f8285bcb5cfc \
+    --hash=sha256:82fee1fc78add43492d3a1898bfa6d8a904cc97d8427f683ed8e798d07761aa0
     # via
     #   requests
     #   yarl