chore: bump vendor/zoekt to include CodeQL security fixes

Pulls in sourcebot-dev/zoekt#13 (open), which resolves all open
CodeQL security alerts on the zoekt repo:

- go/clear-text-logging (high) in gitindex/clone.go
- go/incorrect-integer-conversion (high) in api.go and
  zoekt-sourcegraph-indexserver/sg.go
- actions/missing-workflow-permissions (medium x8) in ci.yml and
  buf-breaking-check.yml
- actions/untrusted-checkout/high (high) in semgrep.yml

Also carries through the dependency bumps from sourcebot-dev/zoekt#11
and #12 (go-git 5.18.0, grpc 1.80.0, otel 1.43.0) that were merged
after #1140 so weren't included when main shipped the original zoekt
sync.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: msukkari