Fix parsing of build profile constrains with several terms

Example of Build-Depends that failed to parse:

python3-usb <!nocheck> <!nodoc>

The previous code use ungreedy matching, but anchored to the end of the string, so the result is actually greedy:

/\s*(\<)\s*(.*?)\s*\>$/xp
             ^^

And in the above example, it matched "!nocheck> <!nodoc".

Fixed code explicitly excludes the delimiter.