jobs: remove out-of-date XenServer positions (#3764)

Both Cloud Software Group XenServer listings (Senior Systems Software
Engineer and Lead Systems Software Engineer) now 404 on careers.cloud.com.

Co-authored-by: Daniel Lamping <Daniel.Lamping@citrix.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: 3 people

data/jobs.yml

@@ -1,20 +1,4 @@
 jobs:
-  - title: Senior Systems Software Engineer
-    link: https://careers.cloud.com/jobs/senior-software-engineer-xenserver-toolstack-remote-united-kingdom
-    locations:
-      - Remote
-      - United Kingdom
-    publication_date: 2026-05-15
-    company: Cloud Software Group
-    company_logo: https://www.cloud.com/media_1e40e7d048f0117d4543c940f9e7433b549c08a03.svg
-  - title: Lead Systems Software Engineer
-    link: https://careers.cloud.com/jobs/lead-systems-software-engineer-remote-united-kingdom
-    locations:
-      - Remote
-      - United Kingdom
-    publication_date: 2026-04-08
-    company: Cloud Software Group
-    company_logo: https://www.cloud.com/media_1e40e7d048f0117d4543c940f9e7433b549c08a03.svg
   - title: Compilation engineer
     link: https://www.lasecurecrute.fr/offre-emploi/ingenieur-expert-en-compilation-langages-de-programmation--f-h/normandie/1065497
     locations: