deps: flip pcre2 to tagged tarball — upstream now uses zig-0.16.0 tag (post-fleet-migration cleanup)

Switch .pcre2 from git+ URL pinned at commit 8fb017d to the
zig-0.16.0 tagged tarball at pmarreck/pcre2. Update the flake's
fetchgit rev/hash and the zigPkgCache linkFarm name to match.
Also gitignore zig-pkg/ (local --system cache directory).

Author: pmarreck

.gitignore

@@ -7,3 +7,4 @@ zig-out/
 .zig-cache
 result
 inbox
+zig-pkg/

build.zig.zon

@@ -13,8 +13,8 @@
             .hash = "sqlite_vec-0.1.7-alpha.2-4Cdt0OvwBACYsEQvfmbSw0sUHuXhcwD5PgjGyslHXU2q",
         },
         .pcre2 = .{
-            .url = "git+https://github.com/pmarreck/pcre2#8fb017d8c41587a3eb3ac165b6e743d318c8fcfe",
-            .hash = "pcre2-10.47.0-S7QTbjnVMgAEncX1a_JtH4G6BgDWzC1tCMvL-KOMrM8b",
+            .url = "https://github.com/pmarreck/pcre2/archive/refs/tags/zig-0.16.0.tar.gz",
+            .hash = "pcre2-10.47.0-S7QTbvnVMgDsA1ipkKNj5kVoEda9wcIuZYUpdrTuDaCh",
         },
     },
     .fingerprint = 0x61f89dfe5a676f3c,

flake.nix

@@ -24,8 +24,8 @@
 				};
 				pcre2-src = pkgs.fetchgit {
 					url = "https://github.com/pmarreck/pcre2.git";
-					rev = "8fb017d8c41587a3eb3ac165b6e743d318c8fcfe";
-					hash = "sha256-ru0tyw/GkB0D89ZHMhy+NsrbRPwZJoF5KwOJu7BW24c=";
+					rev = "873ecf6466a0ddf62facfffbd387213249db20bb";
+					hash = "sha256-a37QL33zCTth7qMBtzwjBkUNjmku6kRa0rrz7oSAOxA=";
 					fetchSubmodules = true;
 				};
 
@@ -37,7 +37,7 @@
 						path = sqlite-vec-src;
 					}
 					{
-						name = "pcre2-10.47.0-S7QTbjnVMgAEncX1a_JtH4G6BgDWzC1tCMvL-KOMrM8b";
+						name = "pcre2-10.47.0-S7QTbvnVMgDsA1ipkKNj5kVoEda9wcIuZYUpdrTuDaCh";
 						path = pcre2-src;
 					}
 				];