fix(cmake): fix USE_BUNDLED_DEPS=ON and BUILD_FALCO_UNIT_TESTS=ON

[LucaGuerra]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

Any specific area of the project related to this PR?

Uncomment one (or more) /area <> lines:

/area build

What this PR does / why we need it:

Build was failing when both USE_BUNDLED_DEPS=ON and BUILD_FALCO_UNIT_TESTS=ON were enabled at the same time with linking errors on absl and grpc. This fixes it by reintroducing explicit library linking for the test suite. It is not 100% clear to me why we need this line but I noticed that before this patch the following files would not be linked in the final executable, hence the errors:

../_deps/yamlcpp-build/libyaml-cppd.a
../grpc-prefix/src/grpc/libgrpc++.a
../grpc-prefix/src/grpc/libgrpc.a
../grpc-prefix/src/grpc/libgpr.a
../protobuf-prefix/src/protobuf/target/lib/libprotobuf.a
../c-ares-prefix/src/c-ares/target/lib/libcares.a
../openssl-prefix/src/openssl/target/lib/libssl.a
../openssl-prefix/src/openssl/target/lib/libcrypto.a

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[LucaGuerra]

/milestone 0.38.0

[LucaGuerra]

cc @federico-sysdig

[federico-sysdig]

LGTM (as agreed, for now 😁)
I'm curious to dig deeper into this when I get a chance to understand why we need to get the linked libraries of a target we already link to and link those dependencies once more. The sole exercise to write this down in words is confusing.

[FedeDP]

/approve

[poiana]

LGTM label has been added.

Git tree hash: 829657f76edca535fc9f6a8ba474ea11ed4b7222

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: FedeDP, jasondellaluce, LucaGuerra

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