Make opebao integration aware of skip_compile

The following discussions from !5340 (merged) should be addressed:

@splattael started a discussion:

Question (non-blocking) Did we support for HTTPs or did we never really support it? 😅

Are we planning to introduce HTTPs at some point? 🤔

@cipherboy-gitlab While testing I stumbled upon two things:

opebao always compiles binary despite openbao.skip_compile=true. I believe we should skip the setup/compile step in this case. Skip compilation is the default.
When compiling openbao binary while it's in use (gdk start openbao) the step fails:

$ make openbao-setup

--------------------------------------------------------------------------------
Compiling openbao using internal build system
--------------------------------------------------------------------------------
rm -rf bin/ build-tree/
openbao-mirror is up to date at v2.4.1
ls: cannot access 'patches/internal/*.patch': No such file or directory
cp -pr openbao-mirror build-tree
rm build-tree/.go-version
1.25
cd build-tree && go mod edit -go=1.25
cd build-tree && go mod tidy
cd build-tree && rm -rf .git && git init && git add -A && git commit -m "Initial commit pre-patches" >/dev/null
Initialized empty Git repository in /home/peter/devel/gitlab/gdk/openbao-internal/build-tree/.git/
if [ -n "patches/upstream/0001-Skip-Container-tests-by-default.patch patches/upstream/0002-Add-http-audit-method-1709.patch" ]; then cd build-tree && git am ../patches/upstream/*.patch ; fi
Applying: Skip Container tests by default
Applying: Add HTTP audit method
Applying: Add documentation on http audit device
Applying: Add warnings against unsafe audit device creation
Applying: Add changelog entry
if [ -n "" ]; then cd build-tree && git am ../patches/internal/*.patch ; fi
mkdir -p bin
cd build-tree && CGO_ENABLED=0 go build -ldflags="-X github.com/openbao/openbao/version.fullVersion=2.4.1 -X github.com/openbao/openbao/version.GitCommit=e5f38fd41e160ce667d226f6455ead95730fa5fa+efb9efa12f550e8322f3cec040862355e966f565 -X github.com/openbao/openbao/version.BuildDate=2025-10-17T04:54:22Z -X github.com/openbao/openbao/version.VersionMetadata=gitlab.1 " -o ../bin/bao
cp: cannot create regular file '/home/peter/devel/gitlab/gdk/openbao/bin/bao': Text file busy
make[1]: *** [support/makefiles/Makefile.openbao.mk:30: openbao-compile] Error 1
make: *** [support/makefiles/Makefile.timing.mk:3: openbao-setup-timed] Error 2

Let's follow-up on this 🙏