ci: remove explicit permissions block in bencher.yml (#35142)

This is causing a validation error because Github's static analysis sees
nightly.yml is calling bencher.yml but the latter requires permissions
that are more relaxed than the former (for android & ohos). Since other
workflows are not failing validation, they presumably already run with
default permissions that are satisfy bencher.yml's requirements
(bencher.yml is not relaxing the parent workflow's permissions as that
would defeat the usefulness of the validation that Github is enforcing).

In the long run we should move to default-restrictive permissions and
then have the top-level workflows declare the required permissions. The
permissions in bencher.yml seems to serve only as machine-checked
documentation, but as it is causing issues with nested calls that are
not possible at runtime, it seems like we have to either pass additional
permissions in top-level workflows (that are not needed, so that is bad)
or not declare them in nested workflows.

Fixes #35141.

Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>

.github/workflows/bencher.yml

@@ -35,10 +35,6 @@ on:
         default: false
         type: boolean
 
-permissions:
-  checks: write
-  pull-requests: write
-
 env:
   RUST_BACKTRACE: 1
   SHELL: /bin/bash