ci: strip mksnapshot binaries on Linux (#22145)

Related to #21086.

.circleci/config.yml

@@ -555,6 +555,7 @@ step-mksnapshot-build: &step-mksnapshot-build
     name: mksnapshot build
     command: |
       cd src
+      ninja -C out/Default electron:electron_mksnapshot -j $NUMBER_OF_NINJA_PROCESSES
       if [ "`uname`" != "Darwin" ]; then
         if [ "$TARGET_ARCH" == "arm" ]; then
           electron/script/strip-binaries.py --file $PWD/out/Default/clang_x86_v8_arm/mksnapshot
@@ -562,6 +563,7 @@ step-mksnapshot-build: &step-mksnapshot-build
           electron/script/strip-binaries.py --file $PWD/out/Default/clang_x64_v8_arm64/mksnapshot
         else
           electron/script/strip-binaries.py --file $PWD/out/Default/mksnapshot
+          electron/script/strip-binaries.py --file $PWD/out/Default/v8_context_snapshot_generator
         fi
       fi
       if [ "$SKIP_DIST_ZIP" != "1" ]; then

BUILD.gn

@@ -1352,12 +1352,18 @@ dist_zip("electron_chromedriver_zip") {
   ]
 }
 
+mksnapshot_deps = [
+  ":licenses",
+  "//tools/v8_context_snapshot:v8_context_snapshot_generator",
+  "//v8:mksnapshot($v8_snapshot_toolchain)",
+]
+
+group("electron_mksnapshot") {
+  public_deps = mksnapshot_deps
+}
+
 dist_zip("electron_mksnapshot_zip") {
-  data_deps = [
-    "//v8:mksnapshot($v8_snapshot_toolchain)",
-    "//tools/v8_context_snapshot:v8_context_snapshot_generator",
-    ":licenses",
-  ]
+  data_deps = mksnapshot_deps
   outputs = [
     "$root_build_dir/mksnapshot.zip",
   ]