Update template and contribution guide

[stutiibm]

Checklist

• Have you checked and followed all the points mention in the CONTRIBUTING.MD
• Have you validated script on UBI 9 container
• Did you run the script(s) on fresh container with set -e option enabled and observe success ?
• Did you have Legal approvals for patch files ?

• docs: update CONTRIBUTING.md to reflect multi-UBI pipeline and strict validation rules

• Make '# Tested on : UBI:.' header mandatory; CI hard-blocks if missing
• Add build_info.json version block key exact-match requirement and wildcard exemption
• Document Stage 0 (check_changes) gating downstream jobs on relevant file changes
• Rewrite Stage 1 (build_info): PACKAGE_VERSION tracking, key validation, per-UBI outputs
• Replace single build stage with parallel build_ubi8/9/10 jobs
• Document 10-job wheel matrix (UBI8 py311/312, UBI9 py310–314, UBI10 py312–314)
• Note suffix addition skipped in PR builds when COS credentials are absent
• Replace flat pipeline flow text with ASCII tree diagram

• docs: update build_info_template.json with UBI routing, auditwheel_exclude, and key-match note

• Add inline NOTE to 'version' field: version block keys must exactly match
  this value (e.g. 'v1.12.0' field → key must be 'v1.12.0', not '1.12.0')
• Add 'auditwheel_exclude' field documenting the array of shared-library
  glob patterns excluded from auditwheel repair (e.g. libcuda.so*)
• Rename version block descriptor key to state the exact-match rule and
  wildcard (*) exemption explicitly
• Expand 'build_script' in version block to document array form: when
  multiple UBI targets are needed, provide one script per UBI major
  (UBI8, UBI9, UBI10); each script's '# Tested on' header determines
  which build job picks it up

• Added ubi8 related information

[janani66]

I have reviewed the changes. @nikhil-kalbande -- would like you to review too.

[janani66]

LGTM