Prep for v1.51.0

[odow]

Basic

• version field of Project.toml has been updated
  - If a breaking change, increment the MAJOR field and reset others to 0
  - If adding new features, increment the MINOR field and reset PATCH to 0
  - If adding bug fixes or documentation changes, increment the PATCH field

Documentation

• Add a new entry to docs/src/changelog.md, following existing style

Tests

• https://github.com/jump-dev/MathOptInterface.jl/actions/runs/24864241664
• https://github.com/jump-dev/MathOptInterface.jl/actions/runs/24974886579
  • Uno failure is because their main can depend on unreleased Uno_jll
  • EAGO is a known issue
  • Optim looks unrelated
  • FrankWolfe looks unrelated
• If new tests were added, ensure that MOI.Test.version_added is implemented.

[odow]

Merging and tagging because we've discussed all of this.