v0.44.0

AbstractAlgebra v0.44.0

Diff since v0.43.12

Merged pull requests:

• Refactor polysubst.jl (#1889) (@lgoettgens)
• Change similar, zero_matrix, ones_matrix to use UndefInitializer constructors (#1909) (@fingolfin)
• fix: multivariate polynomial rings over zero rings (#1910) (@thofma)
• Solve triu (#1920) (@fieker)
• Add generic dispatch for ideal_type (#1924) (@fingolfin)
• Set version to 0.44.0-DEV (#1925) (@fingolfin)
• Set version to 0.44.0 (#1926) (@lgoettgens)