Upgrade to rav1e v0.5.1

Also uncomment the cache hit check in the "Build GoogleTest" step in
.github/workflows/ci-windows.yml.
diff --git a/.github/workflows/ci-windows.yml b/.github/workflows/ci-windows.yml
index 401141a..48714a3 100644
--- a/.github/workflows/ci-windows.yml
+++ b/.github/workflows/ci-windows.yml
@@ -75,7 +75,7 @@
       working-directory: ./ext
       run: ./zlibpng.cmd
     - name: Build GoogleTest
-      #if: steps.cache-ext.outputs.cache-hit != 'true'
+      if: steps.cache-ext.outputs.cache-hit != 'true'
       working-directory: ./ext
       run: ./googletest.cmd
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index da506a0..63fafd2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
 
 ### Changed
 * Update aom.cmd: v3.4.0
+* Update rav1e.cmd: v0.5.1
 * Update svt.cmd/svt.sh: v1.2.1
 * Update libgav1.cmd: v0.18.0
 * Update libyuv.cmd: 9b17af9b (version 1838)
diff --git a/ext/rav1e.cmd b/ext/rav1e.cmd
index b546a75..fab3717 100755
--- a/ext/rav1e.cmd
+++ b/ext/rav1e.cmd
@@ -10,7 +10,7 @@
 : #
 : # On a successful local build, rav1e/build.libavif/ should contain the necessary headers and static library.
 
-git clone -b 0.5 --depth 1 https://github.com/xiph/rav1e.git
+git clone -b v0.5.1 --depth 1 https://github.com/xiph/rav1e.git
 
 cd rav1e
 cargo install cargo-c
diff --git a/tests/docker/build.sh b/tests/docker/build.sh
index 9e6c4cc..2bdf1da 100644
--- a/tests/docker/build.sh
+++ b/tests/docker/build.sh
@@ -63,7 +63,7 @@
 
 # rav1e
 cd
-git clone -b 0.5 --depth 1 https://github.com/xiph/rav1e.git
+git clone -b v0.5.1 --depth 1 https://github.com/xiph/rav1e.git
 cd rav1e
 cargo cinstall --prefix=/usr --release