CompatHelper: bump compat for ParametricOptInterface to 0.15, (keep existing compat) (#343)

Co-authored-by: CompatHelper Julia <compathelper_noreply@julialang.org>

Author: github-actions[bot]

Project.toml

@@ -1,7 +1,7 @@
 name = "DiffOpt"
 uuid = "930fe3bc-9c6b-11ea-2d94-6184641e85e7"
-authors = ["Akshay Sharma", "Mathieu Besançon", "Joaquim Dias Garcia", "Benoît Legat", "Oscar Dowson", "Andrew Rosemberg"]
 version = "0.5.5"
+authors = ["Akshay Sharma", "Mathieu Besançon", "Joaquim Dias Garcia", "Benoît Legat", "Oscar Dowson", "Andrew Rosemberg"]
 
 [deps]
 BlockDiagonals = "0a1fb500-61f7-11e9-3c65-f5ef3456f9f0"
@@ -23,5 +23,5 @@ JuMP = "1"
 LazyArrays = "1, 2"
 MathOptInterface = "1.18"
 MathOptSetDistances = "0.2.9"
-ParametricOptInterface = "0.14.1"
+ParametricOptInterface = "0.14.1, 0.15"
 julia = "1.6"