add back to_power_type to deprecated.jl since some packages call it (#58886)

Co-authored-by: KristofferC <[email protected]>
(cherry picked from commit b6123e8)

Author: KristofferC

base/deprecated.jl

@@ -557,4 +557,11 @@ true
 """
 isbindingresolved
 
+# Some packages call this function
+function to_power_type(x::Number)
+    T = promote_type(typeof(x), typeof(x*x))
+    convert(T, x)
+end
+to_power_type(x) = oftype(x*x, x)
+
 # END 1.12 deprecations