fix: write .version directly instead of hardcoding the version in urls

ci/bump_homebrew_formula.rb now writes Formula/linear-cli/.version to
the release tag directly (the formula's own single source of truth,
per rubyists/homebrew-tap's matching change) instead of rewriting a
literal version number inside each url - the url lines are now a
constant `v#{version}/<asset>` in the formula's own source, so only
the sha256 that follows each one actually needs updating per release.

Verified against a real copy of the formula: correct .version/sha256
output, url lines left untouched, idempotent on a repeated run with
the same inputs, and the resulting formula evaluates to the correct
version/url/sha256 via a small Homebrew-Formula-DSL stub.

Also bumps the vendor/rubyists-homebrew-tap submodule pointer to the
merged fix (rubyists/homebrew-tap#6).

Author: bougyman

ci/bump_homebrew_formula.rb

@@ -1,13 +1,16 @@
 #!/usr/bin/env ruby
-# Bumps a Homebrew formula's per-platform `url`/`sha256` pairs to a new
-# rubyists/linear-cli release - the `.github/workflows/main.yaml`
-# `homebrew-tap-bump` job's only real logic, kept out of the workflow YAML
-# so it's runnable/testable locally without a real CI run.
+# Bumps a Homebrew formula to a new rubyists/linear-cli release: writes
+# `.version` (the formula's own single source of truth - it interpolates
+# `#{version}` into each `url` itself, see the formula file, so the url
+# lines never need touching here) and updates each platform's `sha256`.
+# The `.github/workflows/main.yaml` `homebrew-tap-bump` job's only real
+# logic, kept out of the workflow YAML so it's runnable/testable locally
+# without a real CI run.
 #
 # Usage: bump_homebrew_formula.rb FORMULA_PATH TAG SHA256SUMS_PATH
 #
 #   FORMULA_PATH     path to the formula file (e.g. Formula/linear-cli/linear-cli.rb)
-#   TAG              the release tag, e.g. "v1.3.0"
+#   TAG              the release tag, e.g. "v1.4.0"
 #   SHA256SUMS_PATH  that release's own SHA256SUMS asset, as downloaded
 
 formula_path, tag, sha256sums_path = ARGV
@@ -22,27 +25,30 @@
     acc[name.strip] = sha if name
   end
 
+version = tag.delete_prefix("v")
+version_file = File.join(File.dirname(formula_path), ".version")
+File.write(version_file, "#{version}\n")
+
 content = File.read(formula_path)
 
 %w[macos_aarch64 linux_x86_64].each do |target|
   asset = "lc_#{target}.tar.gz"
   sha = sha256sums.fetch(asset) { abort "No checksum found for #{asset} in #{sha256sums_path}" }
 
+  # The url line is a constant - it always reads v#{version}/<asset>
+  # verbatim in the formula's own source, never a literal version - only
+  # the sha256 that follows it actually changes per release.
   pattern = /
-    url\ "https:\/\/github\.com\/rubyists\/linear-cli\/releases\/download\/v[\d.]+\/#{Regexp.escape(asset)}"
-    \n(\s*)
-    sha256\ "[a-f0-9]+"
+    (url\ "https:\/\/github\.com\/rubyists\/linear-cli\/releases\/download\/v\#\{version\}\/#{Regexp.escape(asset)}"
+    \n\s*sha256\ ")[a-f0-9]+(")
   /x
 
   unless content.match?(pattern)
     abort "Could not find a url/sha256 pair for #{asset} in #{formula_path}"
   end
 
-  content = content.sub(pattern) do
-    indent = ::Regexp.last_match(1)
-    %(url "https://github.com/rubyists/linear-cli/releases/download/#{tag}/#{asset}"\n#{indent}sha256 "#{sha}")
-  end
+  content = content.sub(pattern, "\\1#{sha}\\2")
 end
 
 File.write(formula_path, content)
-puts "Bumped #{formula_path} to #{tag}"
+puts "Wrote #{version_file} (#{version}) and updated #{formula_path}'s sha256 pairs to match"