chore(deps): bump Go from 1.26.4 to 1.26.5

[infernus01]

Changes

Bump the Go toolchain version from 1.26.4 to 1.26.5 to
remediate stdlib CVEs
CVEs fixed by this change:

• CVE-2026-39822 (Important) — stdlib, fixed in Go 1.26.5
• CVE-2026-42505 (Moderate) — stdlib, fixed in Go 1.26.5

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• Has Docs included if any changes are user facing
• Has Tests included if any functionality added or changed
• Follows the commit message standard
• Meets the Tekton contributor standards (including
  functionality, content, code)
• Release notes block below has been updated with any user facing changes (API changes, bug fixes, changes requiring upgrade notices or deprecation warnings)
• Release notes contains the string "action required" if the change requires additional action from users switching to the new release

Release Notes

NONE

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.65%. Comparing base (93ff01b) to head (d7e7e4f).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1904      +/-   ##
==========================================
+ Coverage   72.60%   72.65%   +0.05%     
==========================================
  Files          58       58              
  Lines        3855     3855              
==========================================
+ Hits         2799     2801       +2     
+ Misses        763      761       -2     
  Partials      293      293              

Flag	Coverage Δ
unit-tests	72.65% <ø> (+0.05%)	⬆️

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[enarha]

/lgtm

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: anithapriyanatarajan

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[anithapriyanatarajan]

/lgtm