Client: link the protocols plugin

Context

Fixes #1255 (closed)

This is intended to allow a change in the CI where we delete some old protocols in order to speed-up testing of newer protocols.

Manually testing the MR

git checkout master
rm -rf src/proto_000_Ps9mPmXa src/proto_001_PtCJ7pwo src/proto_002_PsYLVpVv src/proto_003_PsddFKi3 src/proto_004_Pt24m4xi src/proto_005_PsBABY5H src/proto_005_PsBabyM1 src/proto_006_PsCARTHA src/proto_007_PsDELPH1
make
dune exec tezt/tests/main.exe -- --test 'Edo: (Proxy) Compare RPC get'
# Witness tezt tails
git checkout raphael-p@fix-client-linking # on this MR's tip now
rm -rf src/proto_000_Ps9mPmXa src/proto_001_PtCJ7pwo src/proto_002_PsYLVpVv src/proto_003_PsddFKi3 src/proto_004_Pt24m4xi src/proto_005_PsBABY5H src/proto_005_PsBabyM1 src/proto_006_PsCARTHA src/proto_007_PsDELPH1
make
dune exec tezt/tests/main.exe -- --test 'Edo: (Proxy) Compare RPC get'
# Witness tezt succeeds

Checklist

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