refactor(Probability): make PMF return NNReal

[BoltonBailey]

This PR refactors the PMF FunLike instance to return an NNReal rather than an ENNReal. Potentially this could make algebraic manipulation of these return values easier.

This is currently heavily LLM generated and unaudited, so this is a WIP.

Zulip discussions:

• #new members > Why is the codomain of PMF in mathlib ENNReal and not NNReal @ 💬
• #new members > Performing arithmetic with ENNReals @ 💬
• #Is there code for X? > Statistical distance for `PMF`s? @ 💬

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[github-actions]

PR summary a637594054

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ coe_apply_lt_top
+ coe_apply_ne_top
+ hasSum_coe_ennreal_one
+ tsum_coe_ennreal
- apply_lt_top
- apply_ne_top

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).