sagemathgh-37132: Fix corners cases of free resolutions

    
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as seen in
```sage
sage: P2.<x,y,z> = ProjectiveSpace(QQ, 2)
sage: S = P2.coordinate_ring()
sage: I = S.ideal(0)
sage: C = I.graded_free_resolution(); C
S(0) <-- 0
sage: C[1]
Ambient free module of rank 0 over the integral domain Multivariate
Polynomial Ring in x, y, z over Rational Field
sage: C[0]
------------------------------------------------------------------------
---
IndexError                                Traceback (most recent call
last)
Cell In[5], line 1
----> 1 C[Integer(0)]

File ~/GitHub/sage/src/sage/homology/free_resolution.py:426, in
FiniteFreeResolution.__getitem__(self, i)
    424     F = FreeModule(self._base_ring, 0)
    425 elif i == self._length:
--> 426     F = FreeModule(self._base_ring, self._maps[i - 1].ncols())
    427 else:
    428     F = FreeModule(self._base_ring, self._maps[i].nrows())

IndexError: list index out of range
sage: C.differential(1)
------------------------------------------------------------------------
---
IndexError                                Traceback (most recent call
last)
Cell In[6], line 1
----> 1 C.differential(Integer(1))

File ~/GitHub/sage/src/sage/homology/free_resolution.py:489, in
FiniteFreeResolution.differential(self, i)
    487 elif i == self._length + 1:
    488     s = FreeModule(self._base_ring, 0)
--> 489     t = FreeModule(self._base_ring, self._maps[i - 2].ncols())
    490     m = s.hom(0, t)
    491 elif i > self._length + 1:

IndexError: list index out of range
```


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### ⌛ Dependencies

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URL: sagemath#37132
Reported by: Kwankyu Lee
Reviewer(s): Travis Scrimshaw