Use json for json blocks in docs.

ci/builders/README.md

@@ -113,7 +113,7 @@ generators and zero or more output artifacts.
 
 The following is the high level structure of the build component:
 
-```yaml
+```json
 {
            "archives": [],
            "drone_dimensions": [],
@@ -143,7 +143,7 @@ as a dependency for global tests. If no CAS archive
 is required `cas_archive": false,` needs to be added to the
 configuration.
 
-```yaml
+```json
 {
   "name": "host_debug",
   "base_path": "out/host_debug/zip_archives/",
@@ -188,7 +188,7 @@ On the `dimensions` section the left column contains the keys and
 the right column contains the allowed values. If multiple values are allowed
 for a key they are separated using `|` (pipe symbol).
 
-```yaml
+```json
 "drone_dimensions": [
   "device_type=none",
   "os=Linux"
@@ -208,7 +208,7 @@ Debian or Ubuntu.
 A dictionary with variables passed to gclient during a gclient sync operation.
 They are usually used to add or remove gclient dependencies.
 
-```yaml
+```json
 "gclient_variables": {
    "download_android_deps": false
 }
@@ -224,7 +224,7 @@ A list of strings representing flags passed to the
 [tools/gn](https://github.com/flutter/engine/blob/main/tools/gn) script. The strings can be in the form of “--flag=value” or
 “--flag” followed by “value”.
 
-```yaml
+```json
 "gn": [
       "--runtime-mode",
       "debug",
@@ -241,7 +241,7 @@ version using a prebuilt dart sdk and also build the embedder examples.
 A dictionary with two keys: “config” which references the configs created by gn
 and “target” which is a list of strings with the Ninja targets to build.
 
-```yaml
+```json
 "ninja": {
     "config": "host_debug",
     "targets": [
@@ -266,7 +266,7 @@ should not reference or use anything outside of the commit checkout or
 the outputs generated by running gn and ninja sections of the build
 configuration.
 
-```yaml
+```json
 "tests": [
    {
        "language": "python3",
@@ -333,7 +333,7 @@ of the script to embed the signing metadata.
 Generators contain a single property “tasks” which is a list of tasks to be
 performed.
 
-```yaml
+```json
 "generators": {
     "tasks": []
  }
@@ -354,7 +354,7 @@ be relative to the checkout directory.
 * **Script**, the script path relative to the checkout repository.
 * **Language**, the script language executable to run the script. If empty it is assumed to be bash.
 
-```yaml
+```json
 {
     "name": "Debug-FlutterMacOS.framework",
     "parameters": [
@@ -391,7 +391,7 @@ by the global generators. Is a list of dictionaries with two keys: `source` and
 `destination`. `source` is a path relative to the checkout repository and
 `destination` is a relative path to <bucket>/flutter/<commit>.
 
-```yaml
+```json
 "archives": [
     {
         "source": "out/debug/artifacts.zip",