The recipe currently skips all analysis when Binary-Size: footer is present.

The rationale was to not slow down devs when they need to add the footer, and that you can always refer to prior patchsets to find the analysis.

We've now seen that:
* Adding Binary-Size: is pretty uncommon
* It's not always accurate to look at older patchsets (changes can happen after origin patchset)

We should remove the short-circuit logic here:

https://cs.chromium.org/chromium/build/scripts/slave/recipes/binary_size_trybot.py?rcl=0d10eb44532003a23b2fd831fb37db2838eabb8b&l=78