upgrading to boost v1.81.0; modifying with new version number

Author: andrjohns

make/libraries

@@ -8,7 +8,7 @@ endef
 # Library locations
 
 MATH ?=
-BOOST ?= $(MATH)lib/boost_1.78.0
+BOOST ?= $(MATH)lib/boost_1.81.0
 EIGEN ?= $(MATH)lib/eigen_3.4.0
 OPENCL ?= $(MATH)lib/opencl_3.0.0
 TBB ?= $(MATH)lib/tbb_2020.3