Updating Observability team references

...architecture/design-documents/capacity_planning/_index.md

...esign-documents/cells/infrastructure/cell_arch_tooling.md

...chitecture/design-documents/disaster_recovery/regional.md

.../architecture/design-documents/disaster_recovery/zonal.md

...engineering/development/ops/deploy/environments/_index.md

content/handbook/engineering/error-budgets/_index.md

...frastructure-platforms/data-access/gitaly/debug/_index.md

...ook/engineering/infrastructure/capacity-planning/index.md

...ngineering/infrastructure/team/gitlab-dedicated/_index.md

...k/engineering/infrastructure/team/observability/_index.md

...ng/infrastructure/team/observability/capacity_planning.md

...ook/engineering/infrastructure/team/observability/cost.md

...eering/infrastructure/team/observability/error_budgets.md

.../infrastructure/team/observability/technical_blueprint.md

...ook/engineering/infrastructure/team/scalability/_index.md