Update installer to reflect new GitHub HTML

Fixes helm/helm#10266

Signed-off-by: Dan Russell <dpr@aol.com>

scripts/get-helm-3

@@ -105,9 +105,9 @@ checkDesiredVersion() {
     # Get tag from release URL
     local latest_release_url="https://github.com/helm/helm/releases"
     if [ "${HAS_CURL}" == "true" ]; then
-      TAG=$(curl -Ls $latest_release_url | grep 'href="/helm/helm/releases/tag/v3.[0-9]*.[0-9]*\"' | grep -v no-underline | head -n 1 | cut -d '"' -f 2 | awk '{n=split($NF,a,"/");print a[n]}' | awk 'a !~ $0{print}; {a=$0}')
+      TAG=$(curl -Ls $latest_release_url | grep 'href="/helm/helm/releases/tag/v3.[0-9]*.[0-9]*\"' | sed -E 's/.*\/helm\/helm\/releases\/tag\/(v[0-9\.]+)".*/\1/g' | head -1)
     elif [ "${HAS_WGET}" == "true" ]; then
-      TAG=$(wget $latest_release_url -O - 2>&1 | grep 'href="/helm/helm/releases/tag/v3.[0-9]*.[0-9]*\"' | grep -v no-underline | head -n 1 | cut -d '"' -f 2 | awk '{n=split($NF,a,"/");print a[n]}' | awk 'a !~ $0{print}; {a=$0}')
+      TAG=$(wget $latest_release_url -O - 2>&1 | grep 'href="/helm/helm/releases/tag/v3.[0-9]*.[0-9]*\"' sed -E 's/.*\/helm\/helm\/releases\/tag\/(v[0-9\.]+)".*/\1/g' | head -1)
     fi
   else
     TAG=$DESIRED_VERSION