fix(CI): Build in current dir in build-qtox-linux.sh

Matches Windows and AppImage build script behaviour.

Irrelevant for CI runs, but since the build dir is inside the user's mounted
qTox dir, this stops manual runs from deleting a possibly existing directory,
and allows the user to chose the build dir.

Requires removing of the check for committed generated cmake files, but I can't
imagine those making it past review anyway.

.ci-scripts/build-qtox-linux.sh

@@ -46,13 +46,8 @@ if [ -z "${BUILD_TYPE+x}" ]; then
 fi
 
 SRCDIR=/qtox
-BUILDDIR=/qtox/build
 export CTEST_OUTPUT_ON_FAILURE=1
 
-rm -fr "$BUILDDIR"
-mkdir -p "$BUILDDIR"
-cd "$BUILDDIR"
-
 if [ $MINIMAL -eq 1 ]; then
     cmake "$SRCDIR" \
         -DCMAKE_BUILD_TYPE=$BUILD_TYPE \
@@ -70,8 +65,3 @@ fi
 
 cmake --build . -- -j $(nproc)
 cmake --build . --target test
-
-echo "Checking whether files processed by CMake have been committed..."
-echo ""
-# ↓ `0` exit status only if there are no changes
-git diff --exit-code

.ci-scripts/lcov.sh

@@ -16,6 +16,6 @@
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # Create lcov report
-lcov --directory /qtox/build --capture --output-file coverage.info
+lcov --directory . --capture --output-file coverage.info
 # Filter out system headers and test sources
 lcov --remove coverage.info '/usr/*' '*/test/*' '*/*_autogen/*' --output-file coverage.info