Update Julia Solver Dependencies and NLR API Key Environment Variables

[Bill-Becker]

This pull request makes two unrelated updates:

1. Upgrades several dependencies in the Julia environment (julia_src folder) for the optimization solver stack (HiGHS, JuMP, MathOptInterface). We had found peculiar optimization results for a scenario with tiered rates where it was solving with a negative NPV of larger magnitude than the tolerance. The solver stack upgrade fixed it. It also removes some unused dependencies.
2. Environment variable names related to the NREL/NLR developer API key and email. The changes help align the API codebase with new naming conventions of REopt.jl API key environment variable names.

Environment variable renaming:

• Changed all references of NREL_DEVELOPER_API_KEY and NREL_DEVELOPER_EMAIL to NLR_DEVELOPER_API_KEY and NLR_DEVELOPER_EMAIL in the julia_src dirctory .env file and http.jl which uses that. This affects how API keys and emails are loaded and set for requests. [1] [2] [3] [4]

Dependency updates and removals:

• Upgraded key dependencies in Manifest.toml, including HiGHS (from 1.15.0 to 1.24.1), HiGHS_jll, JuMP (from 1.25.0 to 1.31.1), and MathOptInterface (from 1.39.0 to 1.52.0), and added new dependencies such as MathOptIIS. [1] [2] [3]
• Removed unused dependencies: BenchmarkTools, JSON3, Profile, and StructTypes from Manifest.toml, cleaning up the dependency tree. [1] [2] [3] [4]

[Copilot]

Pull request overview

This PR updates the Julia-side solver environment to newer versions (HiGHS/JuMP/MathOptInterface stack) and renames internally-used developer credential environment variables from NREL_* to NLR_* within julia_src, aligning with updated REopt.jl conventions.

Changes:

• Upgrade Julia solver stack dependencies and adjust the dependency graph in julia_src/Manifest.toml (including adding MathOptIIS and removing some previously-used packages).
• Rename internal developer key/email environment variables used by the Julia HTTP server (julia_src/http.jl) and its .env.
• Record the changes in CHANGELOG.md under v3.22.1.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
julia_src/Manifest.toml	Upgrades solver stack packages (HiGHS/JuMP/MOI) and updates dependency resolution.
julia_src/http.jl	Renames env var usage for developer key/email and continues request-time key handling logic.
julia_src/.env	Renames env vars for local/default Julia server configuration.
CHANGELOG.md	Adds a v3.22.1 entry documenting the solver/env-var updates.

Suppressed comments (1)

julia_src/http.jl:916

• Same concurrency issue as /reopt: mutating global ENV["NLR_DEVELOPER_API_KEY"] inside the request handler can leak keys across concurrent requests. Prefer passing request-specific credentials explicitly (or otherwise isolating them) rather than relying on a process-global env var.

        if !isempty(get(d, "api_key", ""))
            ENV["NLR_DEVELOPER_API_KEY"] = pop!(d, "api_key")
        else
            ENV["NLR_DEVELOPER_API_KEY"] = test_nlr_developer_api_key
            delete!(d, "api_key")
        end

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