[Trivial] Remove warning

[NAThompson]

When integrating Symbolics.jl with Latexify and ImageInTerminal, the following warning is emitted:

WARNING: method definition for supremum at /Users/nathompson7/.julia/packages/Symbolics/HDE84/src/domains.jl:22 declares type variable T but does not use it.

Fix it by removing the variable declaration.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes are missing coverage. Please review.

Project coverage is 10.12%. Comparing base (79c4e92) to head (f971801).
Report is 164 commits behind head on master.

Files	Patch %	Lines
src/domains.jl	0.00%	2 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #1137       +/-   ##
===========================================
- Coverage   77.07%   10.12%   -66.95%     
===========================================
  Files          32       35        +3     
  Lines        3533     3623       +90     
===========================================
- Hits         2723      367     -2356     
- Misses        810     3256     +2446     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[NAThompson]

To reproduce:

using Latexify
using Symbolics
using ImageInTerminal

function main()
    @variables x::Real y::Real

    expression = 2*x*y
    latexify(expression) |> s -> render(s, dpi=400)
end

if !isinteractive()
    main()
end

Output:

WARNING: Method definition isapprox(IntervalSets.AbstractInterval{T} where T, IntervalSets.AbstractInterval{T} where T) in module IntervalSets at ~/.julia/packages/IntervalSets/kyCuf/src/IntervalSets.jl:296 overwritten in module DomainSets at ~/.julia/packages/DomainSets/aafhp/src/domains/interval.jl:52.
ERROR: Method overwriting is not permitted during Module precompilation. Use `__precompile__(false)` to opt-out of precompilation.
WARNING: Method definition isapprox(IntervalSets.AbstractInterval{T} where T, IntervalSets.AbstractInterval{T} where T) in module IntervalSets at ~/.julia/packages/IntervalSets/kyCuf/src/IntervalSets.jl:296 overwritten in module DomainSets at ~/.julia/packages/DomainSets/aafhp/src/domains/interval.jl:52.
ERROR: Method overwriting is not permitted during Module precompilation. Use `__precompile__(false)` to opt-out of precompilation.
WARNING: method definition for supremum at ~/.julia/packages/Symbolics/HDE84/src/domains.jl:22 declares type variable T but does not use it.

Additional information:

$ julia --version
julia version 1.10.3