android build: p4a to build pyqt5 using "hostpython" instead of sys py

The current system python in the docker baseimage is py3.9, while the
targetpython and hostpython built by p4a are py3.8, and this was causing
linker issues in the pyqt5 build.
It is also cleaner IMHO to have p4a handle what is needed for a recipe
instead of assuming it is available in the system. (and I think this is
how other existing recipes work)

fixes https://github.com/spesmilo/electrum/issues/8016

contrib/deterministic-build/requirements-build-android.txt

@@ -115,9 +115,6 @@ ptyprocess==0.7.0 \
 pyparsing==3.0.7 \
     --hash=sha256:18ee9022775d270c55187733956460083db60b37d0d0fb357445f3094eed3eea \
     --hash=sha256:a6c06a88f252e6c322f65faf8f418b16213b51bdfaece0524c1c1bc30c63c484
-PyQt-builder==1.12.2 \
-    --hash=sha256:48f754394d235307201ec2b5355934858741201af09433ff543ca40ae57b7865 \
-    --hash=sha256:f62bb688d70e0afd88c413a8d994bda824e6cebd12b612902d1945c5a67edcd7
 pytoml==0.1.21 \
     --hash=sha256:57a21e6347049f73bfb62011ff34cd72774c031b9828cb628a752225136dfc33 \
     --hash=sha256:8eecf7c8d0adcff3b375b09fe403407aa9b645c499e5ab8cac670ac4a35f61e7
@@ -127,12 +124,6 @@ setuptools==61.3.1 \
 sh==1.14.2 \
     --hash=sha256:4921ac9c1a77ec8084bdfaf152fe14138e2b3557cc740002c1a97076321fce8a \
     --hash=sha256:9d7bd0334d494b2a4609fe521b2107438cdb21c0e469ffeeb191489883d6fe0d
-sip==6.5.1 \
-    --hash=sha256:01a637b44c5918505801c3d56e1e010b8e86a4edee71c0bd8541c54387b57ae2 \
-    --hash=sha256:13b09357615c2d8bcb23bf21c1637941ac8ff5f28b346c1ccad7efafa57673e9 \
-    --hash=sha256:204f0240db8999a749d638a987b351861843e69239b811ec3d1881412c3706a6 \
-    --hash=sha256:57e5ac40744c0f10a6c53dd45d2ef2c90e52f34a0210d8309e6563a07f914d0d \
-    --hash=sha256:de1cb4004d75a3a236f82a69cd7a3e51ff76b414df412fea22bf433b28876e3f
 six==1.16.0 \
     --hash=sha256:1e61c37477a1626458e36f7b1d82aa5c9b094fa4802892072e49de9c60c4c926 \
     --hash=sha256:8abb2f1d86890a2dfb989f9a77cfcfd3e47c2a354b01111771326f8aa26e0254