CompatHelper: bump compat for Symbolics to 7 for package docs, (keep existing compat)

Author: CompatHelper Julia

docs/Project.toml

@@ -29,7 +29,7 @@ Documenter = "1"
 DocumenterCitations = "1.3"
 ExponentialUtilities = "1"
 GR = "0"
-IntervalArithmetic = "0.20 - 0.21, =0.21.2"  # v0.22 removed IntervalBox
+IntervalArithmetic = "0.20 - 0.21, =0.21.2"
 IntervalMatrices = "0.8 - 0.12"
 LaTeXStrings = "1"
 MiniQhull = "0.4"
@@ -39,5 +39,5 @@ Polyhedra = "0.7 - 0.8"
 RecipesBase = "1"
 StaticArrays = "1"
 SymEngine = "0.7 - 0.13"
-Symbolics = "6.1"
+Symbolics = "6.1, 7"
 TaylorModels = "0.6 - 0.8"