Revert "Temporarily disable cache"

This reverts commit a6b19f7.

Author: weiji14

.github/workflows/ci_docs.yml

@@ -74,8 +74,8 @@ jobs:
             channels:
               - conda-forge
               - nodefaults
-          cache-downloads: false
-          cache-environment: false
+          cache-downloads: true
+          cache-environment: true
           create-args: >-
             python=3.11
             gmt=6.4.0

.github/workflows/ci_tests.yaml

@@ -103,8 +103,8 @@ jobs:
             channels:
               - conda-forge
               - nodefaults
-          cache-downloads: false
-          cache-environment: false
+          cache-downloads: true
+          cache-environment: true
           create-args: >-
             python=${{ matrix.python-version }}${{ matrix.optional-packages }}
             gmt=6.4.0

.github/workflows/ci_tests_dev.yaml

@@ -98,8 +98,8 @@ jobs:
             channels:
               - conda-forge
               - nodefaults
-          cache-downloads: false
-          cache-environment: false
+          cache-downloads: true
+          cache-environment: true
           create-args: >-
             python=3.11
             cmake

.github/workflows/ci_tests_legacy.yaml

@@ -61,8 +61,8 @@ jobs:
             channels:
               - conda-forge
               - nodefaults
-          cache-downloads: false
-          cache-environment: false
+          cache-downloads: true
+          cache-environment: true
           create-args: >-
             python=3.9
             gmt=${{ matrix.gmt_version }}