Update MAT requirement from 0.10, 0.11 to 0.10, 0.11, 0.12

Updates the requirements on [MAT](https://github.com/JuliaIO/MAT.jl) to permit the latest version.
- [Release notes](https://github.com/JuliaIO/MAT.jl/releases)
- [Commits](https://github.com/JuliaIO/MAT.jl/commits/v0.12.0)

---
updated-dependencies:
- dependency-name: MAT
  dependency-version: 0.12.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

KomaMRIBase/Project.toml

@@ -16,7 +16,7 @@ Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 
 [compat]
 Interpolations = "0.13, 0.14, 0.15, 0.16"
-MAT = "0.10, 0.11"
+MAT = "0.10, 0.11, 0.12"
 MRIBase = "0.4"
 Parameters = "0.12"
 Reexport = "1"