Build failures on 32-bit archs

[jas4711]

Hi! I'm packaging this for Debian and we ran into build problems on 32-bit archs like i386.

https://salsa.debian.org/jas/go-jsonschema/-/jobs/9841441#L1594

# github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes/larger.go:86:56: cannot use -2147483649 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes/larger.go:89:56: cannot use 2147483648 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes/larger.go:101:55: cannot use 4294967296 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes/larger.go:155:56: cannot use -2147483649 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes/larger.go:158:56: cannot use 2147483648 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/largerSizes/larger.go:170:55: cannot use 4294967296 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizes
# github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizes
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizes/restricted.go:95:55: cannot use 4294967294 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizes/restricted.go:173:55: cannot use 4294967294 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences
# github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences/restricted.go:166:52: cannot use -2147483649 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences/restricted.go:183:52: cannot use -2147483649 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences/restricted.go:199:52: cannot use 2147483648 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences/restricted.go:216:52: cannot use 2147483648 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences/restricted.go:408:52: cannot use 4294967296 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
src/github.com/atombender/go-jsonschema/tests/data/minSizedInts/restrictedSizesReferences/restricted.go:422:52: cannot use 4294967296 (untyped int constant) as int value in argument to fmt.Errorf (overflows)
github.com/atombender/go-jsonschema/tests/data/misc/specialCharacters

Thanks,
Simon