Fix the target branch in the upload documentation step

[seladb]

Build doxygen failed on master: https://github.com/seladb/PcapPlusPlus/actions/runs/9637853555/job/26577683049

This is because the default target branch in the target repo (PcapPlusPlus/pcapplusplus.github.io) is main and our docs repo still has master as its root branch. This PR specifies the target branch which should fix the issue

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.66%. Comparing base (80dbe60) to head (9fd9f3c).
Report is 1 commits behind head on dev.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #1462   +/-   ##
=======================================
  Coverage   82.66%   82.66%           
=======================================
  Files         171      171           
  Lines       22585    22585           
  Branches     8559     8559           
=======================================
  Hits        18670    18670           
  Misses       3099     3099           
  Partials      816      816           

Flag	Coverage Δ
alpine317	72.72% <ø> (ø)
fedora37	72.69% <ø> (-0.05%)	⬇️
macos-12	61.50% <ø> (ø)
macos-13	60.55% <ø> (ø)
macos-14	60.55% <ø> (ø)
mingw32	70.67% <ø> (-0.03%)	⬇️
mingw64	70.69% <ø> (ø)
npcap	83.91% <ø> (ø)
rhel93	72.74% <ø> (ø)
ubuntu1804	75.25% <ø> (-0.01%)	⬇️
ubuntu2004	73.69% <ø> (-0.01%)	⬇️
ubuntu2004-zstd	73.65% <ø> (-0.05%)	⬇️
ubuntu2204	72.55% <ø> (ø)
ubuntu2204-icpx	59.07% <ø> (-0.01%)	⬇️
unittest	82.66% <ø> (ø)
windows-2019	83.93% <ø> (ø)
windows-2022	83.93% <ø> (ø)
winpcap	83.90% <ø> (ø)
xdp	60.18% <ø> (ø)

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