Allow EigenvalueTarget in ExplicitImports QA

[ChrisRackauckas-Claude]

This PR should be ignored until reviewed by @ChrisRackauckas.

Summary

• Adds SciMLBase.EigenvalueTarget to the existing ExplicitImports unanalyzable allowlist for EnumX-generated modules.
• Keeps the QA check enabled; this mirrors the existing handling for ReturnCode and AlgorithmInterpretation.

Local verification

• timeout 3600 env GROUP=QA ~/.juliaup/bin/julia +1 --project=. -e 'using Pkg; Pkg.test(; coverage=false)'
  • Result: QA | 15 pass / 15 total; Testing SciMLBase tests passed
• timeout 3600 ~/.juliaup/bin/julia +1 -e 'using Runic; exit(Runic.main(["--check", "."]))'
  • Result: passed
• git diff --check
  • Result: passed

Base failure audit

Clean upstream master c2b0cceef236107656a369c4d5c5aec8f8124d2b fails the same QA command with UnanalyzableModuleException for SciMLBase.EigenvalueTarget.

Sidecar audit identified culprit b892a3809ed8c89cf62215e361ecd11cea4392cc (Add EigenvalueProblem, EigenvalueSolution, and EigenvalueTarget (#1417)), which introduced EigenvalueTarget as an EnumX.@enumx module after the EnumX allowlist was added.

[ChrisRackauckas-Claude]

Scratchpad update: reproduced the QA failure on clean upstream master (c2b0cce) with GROUP=QA, where ExplicitImports errors on SciMLBase.EigenvalueTarget. The branch passes the same local QA command (QA | 15 pass / 15 total), Runic, and git diff --check. Sidecar audit points to b892a380 (#1417) as the introducing commit.

[ChrisRackauckas-Claude]

CI update: the GitHub tests / QA (julia 1, ubuntu-latest) lane now passes on this branch (9m54s). This matches the local GROUP=QA validation and confirms the EigenvalueTarget ExplicitImports allowlist fix in CI.