tests: Upgrade to ninja v1.9 for Linux

Also use the upstream release. This eliminates Meson CI's dependence
on my server.

.travis.yml

@@ -58,7 +58,7 @@ script:
       ci_env=`bash <(curl -s https://codecov.io/env)`
       docker run --security-opt seccomp:unconfined $ci_env -v ${PWD}/.coverage:/root/.coverage \
         withgit \
-          /bin/sh -c "cd /root && mkdir -p tools; wget -c http://nirbheek.in/files/binaries/ninja/linux-amd64/ninja -O /root/tools/ninja; chmod +x /root/tools/ninja; CC=$CC CXX=$CXX OBJC=$CC OBJCXX=$CXX PATH=/root/tools:$PATH MESON_FIXED_NINJA=1 ./run_tests.py $RUN_TESTS_ARGS -- $MESON_ARGS && chmod -R a+rwX .coverage"
+          /bin/sh -c "cd /root && mkdir -p tools; wget -c https://github.com/ninja-build/ninja/releases/download/v1.9.0/ninja-linux.zip -O /root/tools/ninja.zip; unzip -d /root/tools /root/tools/ninja.zip; chmod +x /root/tools/ninja; CC=$CC CXX=$CXX OBJC=$CC OBJCXX=$CXX PATH=/root/tools:$PATH ./run_tests.py $RUN_TESTS_ARGS -- $MESON_ARGS && chmod -R a+rwX .coverage"
     fi
   # Ensure that llvm is added after $PATH, otherwise the clang from that llvm install will be used instead of the native apple clang.
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then SDKROOT=$(xcodebuild -version -sdk macosx Path) CPPFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib OBJC=$CC OBJCXX=$CXX PATH=$HOME/tools:/usr/local/opt/qt/bin:$PATH:$(brew --prefix llvm)/bin ./run_tests.py $RUN_TESTS_ARGS --backend=ninja -- $MESON_ARGS ; fi

run_tests.py

@@ -233,7 +233,7 @@ def ensure_backend_detects_changes(backend):
     # timestamps and not running on HFS+ which only stores dates in seconds:
     # https://developer.apple.com/legacy/library/technotes/tn/tn1150.html#HFSPlusDates
     # FIXME: Upgrade Travis image to Apple FS when that becomes available
-    if (NINJA_1_9_OR_NEWER or ('MESON_FIXED_NINJA' in os.environ)) and not mesonlib.is_osx():
+    if NINJA_1_9_OR_NEWER and not mesonlib.is_osx():
         return
     # This is needed to increase the difference between build.ninja's
     # timestamp and the timestamp of whatever you changed due to a Ninja