rm GDAL_jll hard dependency (not used)

Author: boriskaus

Project.toml

@@ -9,7 +9,6 @@ DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
 FFMPEG = "c87230d0-a227-11e9-1b43-d7ebe4e7570a"
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"
-GDAL_jll = "a7073274-a066-55f0-b90d-d619367d196c"
 GeoParams = "e018b62d-d9de-4a26-8697-af89c310ae38"
 Geodesy = "0ef565a4-170c-5f04-8de2-149903a85f3d"
 GeometryBasics = "5c1252a2-5f33-56bf-86c9-59e7332b4326"
@@ -52,7 +51,6 @@ DelimitedFiles = "1"
 Downloads = "1"
 FFMPEG = "0.4"
 FileIO = "1"
-GDAL_jll = "300 - 304"
 GLMakie = "0.8 - 0.11, 0.13"
 GMT = ">=1.17"
 GeoParams = "0.2 - 0.7"