Don't divide CODEQL_RAM in half

This code in the autobuild.sh script halves memory between the JVM and TS:

https://github.com/github/codeql/blob/59a77a873c894bca7274a7ed7c7c6d937547e9b3/javascript/resources/tools/autobuild.sh#L7-L13

Since CODEQL_RAM appears to be a default variable, consuming most of the Github runner's memory, this script shouldn't be halving the memory allocation as large TS projects hit a `FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory` error. How can we override this halving?