Fix: [CI] no need to build unit-tests for releases (#10759)

We don't run them anyway. And LTO can be darn slow.

.github/workflows/release-linux.yml

@@ -124,7 +124,7 @@ jobs:
 
         echo "::group::Build"
         echo "Running on $(nproc) cores"
-        cmake --build . -j $(nproc)
+        cmake --build . -j $(nproc) --target openttd
         echo "::endgroup::"
 
     - name: Create bundles

.github/workflows/release-macos.yml

@@ -107,7 +107,7 @@ jobs:
 
         echo "::group::Build"
         echo "Running on $(sysctl -n hw.logicalcpu) cores"
-        cmake --build . -j $(sysctl -n hw.logicalcpu)
+        cmake --build . -j $(sysctl -n hw.logicalcpu) --target openttd
         echo "::endgroup::"
 
     - name: Build x64
@@ -130,7 +130,7 @@ jobs:
 
         echo "::group::Build"
         echo "Running on $(sysctl -n hw.logicalcpu) cores"
-        cmake --build . -j $(sysctl -n hw.logicalcpu)
+        cmake --build . -j $(sysctl -n hw.logicalcpu) --target openttd
         echo "::endgroup::"
 
     - name: Create bundles

.github/workflows/release-windows.yml

@@ -133,7 +133,7 @@ jobs:
         echo "::endgroup::"
 
         echo "::group::Build"
-        cmake --build .
+        cmake --build . --target openttd
         echo "::endgroup::"
       env:
         WINDOWS_CERTIFICATE_COMMON_NAME: ${{ secrets.WINDOWS_CERTIFICATE_COMMON_NAME }}
@@ -157,7 +157,7 @@ jobs:
         echo "::endgroup::"
 
         echo "::group::Build"
-        cmake --build .
+        cmake --build . --target openttd
         echo "::endgroup::"
       env:
         WINDOWS_CERTIFICATE_COMMON_NAME: ${{ secrets.WINDOWS_CERTIFICATE_COMMON_NAME }}