ci: fix git protocol

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

README.md

@@ -194,7 +194,7 @@ buildctl build \
 buildctl build \
     --frontend gateway.v0 \
     --opt source=docker/dockerfile \
-    --opt context=git://github.com/moby/moby \
+    --opt context=https://github.com/moby/moby.git \
     --opt build-arg:APT_MIRROR=cdn-fastly.deb.debian.org
 ```
 

hack/util

@@ -46,7 +46,7 @@ currentcontext="."
 cacheFromFlags=""
 cacheToFlags=""
 if [ "$GITHUB_ACTIONS" = "true" ]; then
-  currentref="git://github.com/$GITHUB_REPOSITORY#$GITHUB_REF"
+  currentref="https://github.com/$GITHUB_REPOSITORY.git#$GITHUB_REF"
   if [ -n "$CACHE_FROM" ]; then
     for cfrom in $CACHE_FROM; do
       cacheFromFlags="${cacheFromFlags}--cache-from=$cfrom "