Temporarily require IDAES 2.0/Pyomo 6.5 until IDAES 2.1/Pyomo 6.6 failures are resolved

[lbianchi-lbl]

Summary/Motivation

Complementary to #199 to try to see if we can narrow down the causes for the CI failures we're seeing after IDAES 2.1/Pyomo 6.6

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[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (e1ef58b) 89.49% compared to head (021b049) 89.49%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #203 +/- ## ======================================= Coverage 89.49% 89.49% ======================================= Files 67 67 Lines 8238 8238 ======================================= Hits 7373 7373 Misses 865 865 ```

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