GH-49901: [R] Bump minimum supported R version to 4.2 now that 4.6 is out (#49929)

### Rationale for this change

We don't need to support R 4.1 as a new version is out

### What changes are included in this PR?

Bump minimum supported version to 4.2

### Are these changes tested?

In CI, sure

### Are there any user-facing changes?

Nope
* GitHub Issue: #49901

Authored-by: Nic Crane <thisisnic@gmail.com>
Signed-off-by: Nic Crane <thisisnic@gmail.com>

Author: thisisnic

dev/tasks/macros.jinja

@@ -277,8 +277,6 @@ env:
   {# use filter to cast to string and convert to lowercase to match yaml boolean #}
   {% set is_fork = (not is_upstream_b)|lower %}
 
-{% set r_release = {"ver": "4.2", "rt" : "42"} %}
-{% set r_oldrel = {"ver": "4.1", "rt" : "40"} %}
 
 {%- macro github_set_env(env) -%}
   {% if env is defined %}

dev/tasks/r/github.linux.arrow.version.back.compat.yml

@@ -90,10 +90,8 @@ jobs:
         - { old_arrow_version: '10.0.1', r: '4.2' }
         - { old_arrow_version: '9.0.0', r: '4.2' }
         - { old_arrow_version: '8.0.0', r: '4.2' }
-        - { old_arrow_version: '7.0.0', r: '4.1' }
-        - { old_arrow_version: '6.0.1', r: '4.1' }
-        - { old_arrow_version: '5.0.0', r: '4.1' }
-        - { old_arrow_version: '4.0.0', r: '4.1' }
+        - { old_arrow_version: '7.0.0', r: '4.2' }
+        - { old_arrow_version: '6.0.1', r: '4.2' }
     env:
       ARROW_R_DEV: "TRUE"
       OLD_ARROW_VERSION: {{ '${{ matrix.config.old_arrow_version }}' }}
@@ -102,17 +100,9 @@ jobs:
 
       - name: Prepare RSPM
         run: |
-          old_arrow_version_major=$(echo ${OLD_ARROW_VERSION} | cut -d. -f1)
-          if [ ${old_arrow_version_major} -ge 6 ]; then
-            # Binary arrow packages for Ubuntu 22.04 are available only
-            # for 6.0.0 or later.
-            rspm="https://packagemanager.rstudio.com/cran/__linux__/jammy/latest"
-            echo "RSPM=${rspm}" >> $GITHUB_ENV
-          else
             # testthat requires fs which now requires libuv1-dev. Install it
             # when RSPM isn't available
             sudo apt update && sudo apt install -y -V libuv1-dev
-          fi
       - uses: r-lib/actions/setup-r@v2
         with:
           r-version: {{ '${{ matrix.config.r }}' }}

dev/tasks/r/github.linux.versions.yml

@@ -30,7 +30,6 @@ jobs:
         r_version:
           # We test devel, release, and oldrel in regular CI.
           # This is for older versions
-          - "4.1"
           - "4.2"
           - "4.3"
           - "4.4"

r/DESCRIPTION

@@ -22,7 +22,7 @@ Description: 'Apache' 'Arrow' <https://arrow.apache.org/> is a cross-language
     language-independent columnar memory format for flat and hierarchical data,
     organized for efficient analytic operations on modern hardware. This
     package provides an interface to the 'Arrow C++' library.
-Depends: R (>= 4.1)
+Depends: R (>= 4.2)
 License: Apache License (>= 2.0)
 URL: https://github.com/apache/arrow/, https://arrow.apache.org/docs/r/
 BugReports: https://github.com/apache/arrow/issues