Created yearPLF global variable and replaced 2024 with it

src/lib/components/IntroWarningBillModal.svelte

src/lib/components/ReformsChanges.svelte

src/lib/components/ValueChange.svelte

src/lib/components/ValueChangeCompare.svelte

src/lib/components/ValueChangeGagnantsPerdants.svelte

src/lib/components/budget/BudgetDetailView.svelte

src/lib/components/budget/BudgetLayout.svelte

src/lib/components/test_cases/TestCaseGraph.svelte

src/lib/components/variables/InflationLawButton.svelte

src/lib/components/variables/InflationLawDetails.svelte

src/lib/components/variables/InflationLawInfoModal.svelte

...omponents/variables/VariableReferredScaleParameter.svelte

...omponents/variables/VariableReferredValueParameter.svelte

src/routes/+layout.svelte