German translation for New/Edit Pipeline Schedules Page

Internationalise New/Edit Pipeline Schedules Page (#33948 (moved))

As part of our on-going effort to internationalise GitLab (#4012 (moved))

• German
  • Page title
  • Description label, placeholder, error message and tooltip
  • Interval Pattern label, placeholder, error message and tooltip
  • Cron Timezone label and dropdown header
  • Target Branch label
  • Activated label
  • Save pipeline schedule - Cancel buttons