gh-37773: Allow construction of classical Lie algebras over finite fields
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Many classical Lie algebras are unable to be constructed because they
multiply a rational number times an element in the base ring. If the
base ring is, say, `GF(3)`, then there is no coercion (since not every
element is defined), so we need to force all elements to be in the base
ring during the computation (which might perform a division that goes to
the fraction field, but it will eventually brings us back to a
$\mathbb{Z}$-basis).
Before, this would fail with a `QQ` to `GF(3)` coercion error:
```
sage: sl4 = lie_algebras.sl(GF(3), 4)
```
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### :hourglass: Dependencies
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URL: https://github.com/sagemath/sage/pull/37773
Reported by: Travis Scrimshaw
Reviewer(s): Frédéric Chapoton, Travis Scrimshaw
