rustc_hir_analysis: Remove premature classification of repeats as AnonConstKind::MCG

[InvalidPathException]

Fixes #148822
Tracking issue: #132980

Root cause:

rust/compiler/rustc_hir_analysis/src/collect.rs

Lines 1840 to 1851 in 996a185

	} else if tcx.features().min_generic_const_args() {
	ty::AnonConstKind::MCGConst
	} else if let hir::Node::Expr(hir::Expr {
	kind: hir::ExprKind::Repeat(_, repeat_count),
	..
	}) = tcx.hir_node(tcx.parent_hir_id(const_arg_id))
	&& repeat_count.hir_id == const_arg_id
	{
	ty::AnonConstKind::RepeatExprCount
	} else {
	ty::AnonConstKind::MCGConst
	}

L1840 causes const args to be identified prematurely when the feature is enabled. for repeat array this is problematic because the next else-if at 1842 will not be hit (but it should be).

Fix:
Removed L1840 else-if block, it seems redundant if we move below the L1842 one, but it might have other responsibilities later on?

Testing:
Regression test from the issue.

r? @BoxyUwU

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