Deprecate `URL`-taking `readValue()` methods in `ObjectMapper`, `ObjectReader`

[cowtowncoder]

With FasterXML/jackson-core#1462 URL-taking factory method of JsonFactory will be deprecated, so we need to do the same for higher level readValue() methods of ObjectMapper and ObjectReader.

[cowtowncoder]

cc @sdeleuze regardless of removal (or not) from 3.x, marking URL-taking variants deprecated due to issues, both in 2.20 and 3.0.

[pjfanning]

I removed them from a Scala API in jackson-module-scala v3

[cowtowncoder]

@pjfanning I will be waiting for some feedback from Spring maintainers (as a sort of proxy), but likely will proceed with v3 removal as well.

[sdeleuze]

@cowtowncoder I asked last week the Spring team to comment if those URL-based method were used and likely to be an issue. If you got no feedback I guess you can follow-up on removal for 3.0 from our POV.

[cowtowncoder]

@sdeleuze Thank you for sanity checking. Will proceed.