Update Unitful requirement to 1.28.0 in /docs

[dependabot]

Updates the requirements on Unitful to permit the latest version.

Release notes

Sourced from Unitful's releases.

v1.28.0

Unitful v1.28.0

Diff since v1.27.0

• Dimensionless quantities now support iseven and isodd (#829).
• Quantities that have equal values and equal units now have the same hash (#833). For now, quantities that are equal (isequal) but have different units still have different hashes, see #379.

Merged pull requests:

• Add methods for iseven, isodd (#829) (@​sostock)
• Bump actions/upload-artifact from 5 to 6 (#830) (@​dependabot[bot])
• Add hash method for quantities (#833) (@​sostock)
• Release v1.28.0 (#835) (@​sostock)

Closed issues:

• Should hashing of Quantity{BigFloat} behave differently to those of BigFloat's? (#378)
• Latexify as soft dependency (#665)
• stack overflow when calling iseven and isodd with unitful quantity (#822)
• "Binding undeclared during precompilation" error (#831)

Changelog

Sourced from Unitful's changelog.

v1.28.0 (2026-01-29)

• Dimensionless quantities now support iseven and isodd (#829).
• Quantities that have equal values and equal units now have the same hash (#833). For now, quantities that are equal (isequal) but have different units still have different hashes, see #379.

v1.27.0 (2025-12-08)

• NaNMath.pow and NaNMath.sqrt from NaNMath.jl are supported via a package extension (#824).

v1.26.0 (2025-12-05)

• The aliases degC and degF for °C and °F are added (#826).
• Correct LaTeX printing of affine units (#825).
• Fix a world-age warning on Julia 1.12 (#819).

v1.25.1 (2025-10-18)

• Fix a parsing error on Julia 1.13 (#817).

v1.25.0 (2025-09-16)

• Quantities and units can now be converted to a LaTeX representation using Latexify.jl. This is provided via a package extension and replaces the UnitfulLatexify.jl package (#795).
• This package now requires Julia ≥ 1.6.

v1.24.0 (2025-07-31)

• The alias deg for ° is added (#764).

v1.23.1 (2025-06-10)

• Fix a world-age issue with the new mechanism to preserve the floating-point precision on unit conversion (#790).

v1.23.0 (2025-06-08)

• On Julia ≥ 1.9, dimensionless quantities can now be converted to ForwardDiff.Dual. This is important for compatibility with the SciML ecosystem and is provided via a package extension (#765).
• On Julia ≥ 1.9, @printf and @sprintf can now be used with Unitful quantities. The specified format is applied to the numeric part of the quantity and the unit is appended to that. This is provided via a package extension (#772).
• Certain unit conversions involving units that are defined using non-integer exponents no longer error (#783).
• uconvert now preserves the floating-point precision of quantities in a non-breaking way (#782).

v1.22.1 (2025-05-13)

• The behaviour to preserve the floating-point precision of quantities (#754, added in v1.22.0) is reverted because it is not compatible with IntervalArithmetic.jl (see #758). The feature will be added in a non-breaking way in a future release.

v1.22.0 (2025-01-02)

• Base.big can now be used with quantities (#755).
• Using Base.convert to convert to a unitless quantity no longer errors (#724).
• Using Base.convert to convert to a mixed logarithmic quantity no longer returns wrong results. In cases that returned a result even though it was unknown whether the quantity was a power or root-power quantity, an error is thrown instead (#724).
• uconvert now preserves the floating-point precision of quantities (#754).
• When printing arrays, quantities are now aligned at the decimal point just like unitless numbers (#752).

... (truncated)

Commits

• 51f55a1 Release v1.28.0 (#835)
• f509770 Add hash method for quantities (#833)
• 96aa0c4 Add methods for iseven, isodd (#829)
• 26cb2e6 Bump actions/upload-artifact from 5 to 6 (#830)
• d417002 Release v1.27.0 (#828)
• 84189cf Add NaNMath extension for Unitful quantities (#824)
• 82f27da Release v1.26.0 (#827)
• 113ffbf Bump actions/upload-artifact from 4 to 5 (#821)
• 9c11081 Add degC, degF as aliases for celsuis and fahrenheit (#826)
• 93473fe Add mathrm to affine unit latexifying (#825)
• Additional commits viewable in compare view

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