chore: update to image-spec v1.1.1

[Wwwsylvia]

1. Use the media type regex defined in image-spec v1.1.1 in pack.go
2. Update the doc links to reference image-spec v1.1.1 and distribution-spec v1.1.1

Resolves: #910

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.19%. Comparing base (1b77bfd) to head (181c683).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #909      +/-   ##
==========================================
- Coverage   80.24%   80.19%   -0.05%     
==========================================
  Files          63       63              
  Lines        6053     6053              
==========================================
- Hits         4857     4854       -3     
- Misses        858      860       +2     
- Partials      338      339       +1     

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[Copilot]

PR Overview

This PR updates documentation and code comments to reference image‑spec v1.1.1 along with related distribution‑spec links. It also adjusts the media type regular expression to reflect the new specification.

• Updated references across comments in various files from v1.1.0 to v1.1.1.
• Modified the mediaTypeRegexp in pack.go to match the new image‑spec.
• Updated documentation links in registry and content packages to point to the new spec versions.

Reviewed Changes

File	Description
pack.go	Updated image‑spec documentation and mediaTypeRegexp
registry/remote/repository.go	Updated distribution‑spec references
registry/remote/errcode/errors.go	Updated error code documentation links
registry/repository.go	Updated image‑spec references in comments
registry/remote/warning.go	Updated warning reference links
content/oci/readonlystorage.go	Updated image layout reference
registry/reference.go	Updated references for pulling manifests
content/oci/oci.go	Updated image layout references
registry/remote/registry.go	Updated registry API reference
example_pack_test.go	Updated image‑spec version reference in test example
content/oci/storage.go	Updated image layout reference in comments
content/oci/readonlyoci.go	Updated image layout reference
registry/remote/referrers.go	Updated referrers API documentation references
registry/remote/url.go	Updated URLs documentation references

Copilot reviewed 14 out of 14 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

pack.go:115

• [nitpick] Please verify that the reordering in the mediaTypeRegexp character class accurately reflects the pattern defined in image‑spec v1.1.1 to avoid any unintended matching issues.

var mediaTypeRegexp = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9!#$&^_.+-]{0,126}/[A-Za-z0-9][A-Za-z0-9!#$&^_.+-]{0,126}$`)

[shizhMSFT]

LGTM