DOC: Fix typo in PCG64 (numpy#19538)

* DOC: Fix typo in PCG64

* DOC: fix typo in PCG64DXSM

Author: david-cortes

numpy/random/_pcg64.pyx

@@ -102,7 +102,7 @@ cdef class PCG64(BitGenerator):
 
     **Compatibility Guarantee**
 
-    ``PCG64`` makes a guarantee that a fixed seed and will always produce
+    ``PCG64`` makes a guarantee that a fixed seed will always produce
     the same random integer stream.
 
     References
@@ -338,7 +338,7 @@ cdef class PCG64DXSM(BitGenerator):
 
     **Compatibility Guarantee**
 
-    ``PCG64DXSM`` makes a guarantee that a fixed seed and will always produce
+    ``PCG64DXSM`` makes a guarantee that a fixed seed will always produce
     the same random integer stream.
 
     References