fix: enable -Wcast-qual flag for libcrypto=awslc

[boquan-fang]

Resolved issues:

Resolve issue #4710

Description of changes:

• Remove the condition which only add -Wcast-qual back for non AWS-lc Libcrypto.

Call-outs:

• Waiting for awslc update for ubuntu18.

Testing:

• Local testing without specifying S2N_LIBCRYPTO=openssl.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[goatgoose]

Is there still a reason to have this flag separated from all of the other flags? I wonder if it should just be added to the rest of the options:

s2n-tls/CMakeLists.txt

Lines 137 to 140 in ada65a7

	target_compile_options(${PROJECT_NAME} PRIVATE -pedantic -std=gnu99 -Wall -Wimplicit -Wunused -Wcomment -Wchar-subscripts
	-Wuninitialized -Wshadow -Wcast-align -Wwrite-strings -Wno-deprecated-declarations -Wno-unknown-pragmas -Wformat-security
	-Wno-missing-braces -Wsign-compare -Wno-strict-prototypes -Wa,--noexecstack
	)

[boquan-fang]

The readability will be improved if we put the flag into all of this. I will add -Wcast-qual to this part.