[docs] fix warnings in doc build for resource-groups.rst

[steveburnett]

Two doc build errors are in text in admin/resource-groups.rst added in PR 21057.

/Users/steveburnett/Documents/GitHub/presto/presto-docs/src/main/sphinx/admin/resource-groups.rst:318: WARNING: undefined label: 'jdbc-java-connection'

/Users/steveburnett/Documents/GitHub/presto/presto-docs/src/main/sphinx/admin/resource-groups.rst:330: WARNING: undefined label: 'jdbc-parameter-reference'

I can’t find where these two links should link to.

Expected Behavior

The two warnings are not generated in a doc build.

Current Behavior

The following two errors appear in a local doc build.

/Users/steveburnett/Documents/GitHub/presto/presto-docs/src/main/sphinx/admin/resource-groups.rst:318: WARNING: undefined label: 'jdbc-java-connection'

/Users/steveburnett/Documents/GitHub/presto/presto-docs/src/main/sphinx/admin/resource-groups.rst:330: WARNING: undefined label: 'jdbc-parameter-reference'

Possible Solution

Revise the links in lines 318 and 330

:ref:the example <jdbc-java-connection> and :ref:the example <jdbc-parameter-reference>

to either link to the correct destination, or revise the text to remove the links entirely.

Steps to Reproduce

1. Follow the steps in Building the Documentation to generate a doc build.
2. Examine the output of the build process to find the two warnings.

Context

Builds on the doc build errors and warnings fix work in #23033, #23023, #22876, #22985.