/expand endpoint returns template with additional character when there's a newline

[timhuynh94]

Description

POST /api/v1/pipelines/{org}/{repo}/{pipeline}/expand returns an additional character such as 4 for newline in template
Example vela file:

# instructs Vela which syntax version we're using
version: "1"

# instructs Vela that we're going to create a steps pipeline
steps:
  # instructs Vela what the name of the step should be
  - name: build
    # instructs Vela what Docker image to use for this step
    image: golang:1.21
    # instructs Vela which environment variables to inject for this step
    environment:
      CGO_ENABLED: 0
    # instructs Vela which commands to run inside the step
    commands: |

      git config --global user.email "${VELA_BUILD_SENDER}@git.com"
      git config --global user.name "${VELA_BUILD_SENDER}"

Result:

version: "1"
metadata:
    environment:
        - steps
        - services
        - secrets
steps:
    - commands:
        - |4-
          git config --global user.email "${VELA_BUILD_SENDER}@git.com"
          git config --global user.name "${VELA_BUILD_SENDER}"
      image: golang:1.21
      name: build
      pull: not_present
      environment:
        CGO_ENABLED: "0"

Value

Even though it works, any integration relies on this particular endpoint would fail due to additional character inserted for newline

Useful Information

1. What is the output of vela --version?

v0.23.1

2. What operating system is being used?

3. Any other important details?