Deprecate L34RS tutorials in favor of Cloud OPeNDAP or Harmony

[battistowx]

We will be deprecating L34RS in favor of any of our cloud-enabled subsetting services. This issue captures testing our three existing tutorials on other services, and creating new tutorials that replicate their functionality:

1. https://github.com/nasa/gesdisc-tutorials/blob/main/notebooks/How_to_Use_the_Web_Services_API_for_Subsetting_MERRA-2_Data.ipynb
2. https://github.com/nasa/gesdisc-tutorials/blob/main/notebooks/How_To_Use_the_Web_Services_API_for_Subsetting.ipynb
3. https://github.com/nasa/gesdisc-tutorials/blob/main/notebooks/How_to_Use_the_Web_Services_API_to_Validate_Point_Measurements.ipynb

[battistowx]

Add warning message to each existing on-prem subsetting service how-to